# PHY 101 Concepts for Final Part 1

A) a quantity that is specified by a numerical value only.
A scalar quantity is defined as
A) a quantity that is specified by a numerical value only.
B) a quantity that is specified by using both a numerical value and a direction.
B) a quantity that is specified by using both a numerical value and a direction.
A vector quantity is defined as
A) a quantity that is specified by a numerical value only.
B) a quantity that is specified by using both a numerical value and a direction.
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C) The displacement is either less than or equal to the distance traveled.
Suppose that an object travels from one point in space to another. Make a comparison between the displacement and the distance traveled.
A) The displacement is either greater than or equal to the distance traveled.
B) The displacement is always equal to the distance traveled.
C) The displacement is either less than or equal to the distance traveled.
D) The displacement can be either greater than, smaller than, or equal to the distance traveled.
E) If the displacement is equal to zero, then the distance traveled will also equal zero.
B) The distance between the starting and ending positions is equal to the magnitude of the displacement between the starting and ending positions.
Which statement below about the distance between the starting and ending positions and the displacement between the starting and ending positions is correct?
A) The distance between the starting and ending positions is twice the magnitude of the displacement between the starting and ending positions.
B) The distance between the starting and ending positions is equal to the magnitude of the displacement between the starting and ending positions.
C) The distance between the starting and ending positions is the negative of the magnitude of the displacement between the starting and ending positions.
D) The distance between the starting and ending positions is greater than the magnitude of the displacement between the starting and ending positions.
E) The distance between the starting and ending positions is less than the magnitude of the displacement between the starting and ending positions.
C) less than 70.0 km/h.
You drive 6.00 km at 50.0 km/h and then another 6.00 km at 90.0 km/h. Your average speed over the 12.0 km drive will be
A) greater than 70.0 km/h.
B) equal to 70.0 km/h.
C) less than 70.0 km/h.
D) exactly 38.0 km/h.
E) cannot be determined from the information given, must also know directions traveled
C) average velocity.
The slope of a line connecting two points on a position versus time graph gives
A) displacement.
B) instantaneous velocity.
C) average velocity.
D) instantaneous acceleration.
E) average acceleration.
B) The average speed is always greater than or equal to the magnitude of the average velocity.
Which statement is correct about the relationship between the average speed and the magnitude of the average velocity for any motion?
A) The average speed is always one-half the magnitude of the average velocity.
B) The average speed is always greater than or equal to the magnitude of the average velocity.
C) The average speed can be less than, greater than or equal to the magnitude of the average velocity.
D) The average speed is always less than or equal to the magnitude of the average velocity.
E) The average speed is always equal to the magnitude of the average velocity.
B) instantaneous velocity.
The slope of a tangent line at a given time value on a position versus time graph gives
A) displacement.
B) instantaneous velocity.
C) average velocity.
D) instantaneous acceleration.
E) average acceleration
C) only when the velocity is constant
When is the average velocity of an object equal to the instantaneous velocity?
A) always
B) never
C) only when the velocity is constant
D) only when the velocity is increasing at a constant rate
E) only when the velocity is decreasing at a constant rate
B) The instantaneous speed is always equal to the magnitude of the instantaneous velocity.
Which statement is correct about the relationship between the instantaneous speed and the magnitude of the instantaneous velocity?
A) The average speed can be less than, greater than or equal to the magnitude of the average velocity.
B) The instantaneous speed is always equal to the magnitude of the instantaneous velocity.
C) The average speed is always less than or equal to the magnitude of the average velocity.
D) The instantaneous speed is always greater than or equal to the magnitude of the instantaneous velocity.
E) The average speed is always one-half the magnitude of the average velocity.
D) The acceleration must be equal to zero.
Suppose that an object is moving with a constant velocity. Make a statement concerning its acceleration.
A) The acceleration must be constantly increasing.
B) The acceleration must be constantly decreasing.
C) The acceleration must be a constant non-zero value.
D) The acceleration must be equal to zero.
D) the velocity is not changing at that instant.
At a given instant, the acceleration of a certain particle is zero. This means that
A) the velocity is constant.
B) the velocity is increasing.
C) the velocity is decreasing.
D) the velocity is not changing at that instant.
E) the velocity is zero.
E) average acceleration.
The slope of a line connecting two points on a velocity versus time graph gives
A) displacement.
B) instantaneous velocity.
C) average velocity.
D) instantaneous acceleration.
E) average acceleration.
D) instantaneous acceleration.
The slope of a tangent line at a given time value on a velocity versus time graph gives
A) displacement.
B) instantaneous velocity.
C) average velocity.
D) instantaneous acceleration.
E) average acceleration.
B) In equal times its velocity changes by equal amounts.
Suppose that an object is moving with constant acceleration. Which of the following is an accurate statement concerning its motion?
A) In equal times its speed changes by equal amounts.
B) In equal times its velocity changes by equal amounts.
C) In equal times it moves equal distances.
D) The object is not moving; it is at rest.
A) a straight line.
During the time that the acceleration of a particle is constant, its velocity-vs.-time curve is
A) a straight line.
B) a parabola opening downward.
C) a parabola opening upward.
D) a parabola opening toward the left.
E) a parabola opening toward the right.
A) increases.
The motion of a particle is described in the velocity vs. time graph shown in Figure 2-1. We can say that its speed
A) increases.
B) decreases.
C) increases and then decreases.
D) decreases and then increases.
E) remains constant.
B) The car is decelerating, and its acceleration is negative.
Suppose that a car traveling to the East (+x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its acceleration.
A) The car is decelerating, and its acceleration is positive.
B) The car is decelerating, and its acceleration is negative.
C) The acceleration is zero.
D) A statement cannot be made using the information given.
A) The car is decelerating, and its acceleration is positive.
Suppose that a car traveling to the West (-x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its acceleration.
A) The car is decelerating, and its acceleration is positive.
B) The car is decelerating, and its acceleration is negative.
C) The acceleration is zero.
D) A statement cannot be made using the information given.
C) a straight line making an angle with the time axis.
An object is moving with constant non-zero velocity in the +x-axis. The position versus time graph of this object is
A) a horizontal straight line.
B) a vertical straight line.
C) a straight line making an angle with the time axis.
D) a parabolic curve.
E) a hyperbolic curve.
D) a parabolic curve.
An object is moving with constant non-zero acceleration in the +x-axis. The position versus time graph of this object is
A) a horizontal straight line.
B) a vertical straight line.
C) a straight line making an angle with the time axis.
D) a parabolic curve.
E) a hyperbolic curve.
A) a horizontal straight line.
An object is moving with constant non-zero velocity in the +x-axis. The velocity versus time graph of this object is
A) a horizontal straight line.
B) a vertical straight line.
C) a straight line making an angle with the time axis.
D) a parabolic curve.
E) a hyperbolic curve.
C) a straight line making an angle with the time axis.
An object is moving with constant non-zero acceleration in the +x-axis. The velocity versus time graph of this object is
A) a horizontal straight line.
B) a vertical straight line.
C) a straight line making an angle with the time axis.
D) a parabolic curve.
E) a hyperbolic curve.
C) at rest.
If the position versus time graph of an object is a horizontal line, the object is
A) moving with constant non-zero speed.
B) moving with constant non-zero acceleration.
C) at rest.
D) moving with infinite speed.
E) none of the above
A) moving with constant non-zero speed.
If the velocity versus time graph of an object is a horizontal line, the object is
A) moving with constant non-zero speed.
B) moving with constant non-zero acceleration.
C) at rest.
D) moving with infinite speed.
E) none of the above
B) moving with constant non-zero acceleration.
If the velocity versus time graph of an object is a straight line making an angle of 30 degrees with the time axis, the object is
A) moving with constant non-zero speed.
B) moving with constant non-zero acceleration.
C) at rest.
D) moving with infinite speed.
E) none of the above
B) displacement.
The area under a curve in a velocity versus time graph gives
A) distance traveled.
B) displacement.
C) speed.
D) velocity.
E) acceleration.
A) greater than v0/2.
A car moving initially with velocity v0 with deceleration a comes to a full stop after traveling a distance d. We can say that the velocity of the car after traveling a distance d/2 is
A) greater than v0/2.
B) equal than v0/2.
C) smaller than v0/2.
D) has no relationship to v0.
A car traveling with velocity v is decelerated by a constant acceleration of magnitude a. It travels a distance d before coming to rest. If its initial velocity were doubled, the distance required to stop would
A) double as well.
B) decrease by a factor of two.
C) stay the same.
E) decrease by a factor of four.
A) double as well.
A car traveling with velocity v is decelerated by a constant acceleration of magnitude a. It takes a time t to come to rest. If its initial velocity were doubled, the time required to stop would
A) double as well.
B) decrease by a factor of two.
C) stay the same.
E) decrease by a factor of four.
B) its velocity is zero and its acceleration is not zero.
A stone is thrown straight up. When it reaches its highest point,
A) both its velocity and its acceleration are zero.
B) its velocity is zero and its acceleration is not zero.
C) its velocity is not zero and its acceleration is zero.
D) neither its velocity nor its acceleration is zero.
E) neither velocity nor acceleration can be determined without additional information.
B) Its velocity points upward and its acceleration points downward.
Suppose a ball is thrown straight up, reaches a maximum height, then falls to its initial height. Make a statement about the direction of the velocity and acceleration as the ball is going up.
A) Both its velocity and its acceleration point upward.
B) Its velocity points upward and its acceleration points downward.
C) Its velocity points downward and its acceleration points upward.
D) Both its velocity and its acceleration points downward.
E) Neither velocity nor acceleration can be determined without additional information.
C) twice as long.
Two athletes jump straight up. John has twice the initial speed of Harry. Compared to Harry, John stays in the air
A) 0.50 times as long.
B) 1.41 times as long.
C) twice as long.
D) three times as long.
E) four times as long.
E) four times as long.
Two athletes jump straight up. John has twice the initial speed of Harry. Compared to Harry, John jumps
A) 0.50 times as long.
B) 1.41 times as long.
C) twice as long.
D) three times as long.
E) four times as long.
A) increases.
Two objects are dropped from a bridge, an interval of 1.0 s apart. During the time that both objects continue to fall, their separation
A) increases.
B) decreases.
C) stays constant.
D) increases at first, but then stays constant.
E) decreases at first, but then stays constant.
C) the two balls will have the same speed.
From the edge of a roof top you toss a green ball upwards with initial velocity v0 and a blue ball downwards with the same initial velocity. When they reach the ground below,
A) the green ball will be moving faster than the blue ball.
B) the blue ball will be moving faster than the green ball.
C) the two balls will have the same speed.
A) increases.
You drop a stone from a bridge to the river below. After this stone has traveled a distance d, you drop a second stone. The distance between the two stones will always
A) increases.
B) decreases.
C) stays constant.
D) increases at first, but then stays constant.
E) decreases at first, but then stays constant.
D) mass
Which of the following is a scalar quantity?
A) velocity
B) acceleration
C) displacement
D) mass
E) force
D) displacement
Which of the following is a vector quantity?
A) time
B) mass
C) volume
D) displacement
E) speed
E) The magnitude of a vector cannot be zero unless all of its components are zero.
Which of the following statements is a true statement?
A) A vector can have positive or negative magnitudes.
B) A vector’s magnitude cannot be more than the magnitude of one of its components.
C) A vector’s magnitude cannot be less than the sum of the magnitude of its components.
D) If the x-component of a vector is smaller than its y-component then that vector is in the opposite direction to its y-component.
E) The magnitude of a vector cannot be zero unless all of its components are zero.
A) 0° to 90°.
If a vector A has components Ax > 0, and Ay > 0, then the angle that this vector makes with the positive x-axis must be in the range
A) 0° to 90°.
B) 90° to 180°.
C) 180° to 270°.
D) 270° to 360°.
E) cannot be determined without additional information
C) 180° to 270°.
If a vector A has components Ax < 0, and Ay < 0, then the angle that this vector makes with the positive x-axis must be in the range A) 0° to 90°. B) 90° to 180°. C) 180° to 270°. D) 270° to 360°. E) cannot be determined without additional information
E) depend on the quadrant where A is.
Vector B is obtained by rotating vector A counterclockwise by 270°. The components of B will
A) have the same signs as those of A.
B) have opposite signs as those of A.
C) The x-components will have opposite signs but the y-components will not.
D) The y-components will have opposite signs but the x-components will not.
E) depend on the quadrant where A is.
C) Ax = A cos 0° Bx = -B cos 60° Ay = A cos 90° By = B cos 30°.
Refer to Figure 3-1. The components of vectors A and B are
A) Ax = 0 Bx = B sin 30° Ay = 0 By = B cos 30°.
B) Ax = A sin 90° Bx = B cos 60° Ay = A cos 90° By = B sin 60°.
C) Ax = A cos 0° Bx = -B cos 60° Ay = A cos 90° By = B cos 30°.
D) Ax = A cos 90° Bx = B sin 60° Ay = A sin 90° By = B cos 60°.
E) Ax = A cos 90° Bx = 0 Ay = A sin 90° By = 0
A) It is pointing 20° west of south.
Vector A is initially pointing eastward. This vector is rotated clockwise by an angle of 110°. Which of the following statements is correct regarding the final position of vector A?
A) It is pointing 20° west of south.
B) It is pointing 70° south of east.
C) It is pointing 20° south of west.
D) It is pointing 70° east of south.
E) cannot be determined without additional information
E) The westward component of vector A is equal to the eastward component of vector B.
Vector A has a magnitude of 16.0 m and is pointing eastward. Vector B also has a magnitude of 16.0 m and is pointing westward. Vector is rotated clockwise by 110° and vector is rotated counterclockwise by 110°. Which one of the following statements is correct?
A) The northward component of vector A is bigger than the northward component of vector B.
B) The southward component of vector A is bigger than the southward component of vector B.
C) The eastward component of vector A is bigger than the westward component of vector B.
D) The westward component of vector A is bigger than the eastward component of vector B.
E) The westward component of vector A is equal to the eastward component of vector B.
D) Magnitude of vector A is equal to the magnitude of vector B.
The eastward component of vector A is equal to the westward component of vector B and their northward components are equal. Which one of the following statements is correct for these two vectors?
A) Vector A is parallel to vector B.
B) Vector A is anti-parallel to vector B.
C) Vector A is perpendicular to vector B.
D) Magnitude of vector A is equal to the magnitude of vector B.
E) Magnitude of vector A is twice the magnitude of vector B.
E) Vector A does not have any component along the y-axis and vector B does not have any component along the x-axis.
Vector A is along the x-axis and vector B is along the y-axis. Which one of the following statements is correct with respect to these vectors?
A) The x-component of vector A is equal to the x-component of vector B.
B) The y-component of vector A is equal to the y-component of vector B.
C) The x-component of vector A is equal and opposite to the x-component of vector B.
D) The y-component of vector B is equal and opposite to the y-component of vector A.
E) Vector A does not have any component along the y-axis and vector B does not have any component along the x-axis.
D) 0°.
The sum of two vectors has the greatest magnitude when the angle between these two vectors is
A) 90°.
B) 180°.
C) 60°.
D) 0°.
E) 270°.
D) 180°
The resultant vector C of two vectors A and B will have the minimum value when the angle between these vectors is one of the following?
A) 0°.
B) 90°.
C) 270°
D) 180°
E) 360°
D) Vectors A and B must be perpendicular.
When vectors A and B are added together they form vector C and these vectors satisfy the relationship A2 + B2 = C2. Which statement is true for these vectors?
A) Vectors A and B must be parallel.
B) Vectors A and B must be anti-parallel.
C) Vectors A and B must have the same magnitudes.
D) Vectors A and B must be perpendicular.
E) The magnitude of A is the negative of the magnitude of B.
E) Vectors M and N have the same lengths.
Vectors M and N satisfy the equation M + N = 0. These vectors satisfy one of the following statements.
A) Vectors M and N are at right angles to each other.
B) Vectors M and N point in the same direction.
C) The magnitude of M is the negative of the magnitude of N.
D) The magnitude of M is twice the magnitude of N.
E) Vectors M and N have the same lengths.
A) 8.0 m
A vector A and an anti parallel vector B when added together give a resultant vector C that has a magnitude of 1.0 m. If vector A has a magnitude of 7.0 m, which of the following is a possible magnitude of vector B?
A) 8.0 m
B) 7.0 m
C) 2.4 m
D) 6.9 m
E) 9.0 m
B) M – N.
Refer to Figure 3-2. Vector S as expressed in terms of vectors M and N is given by
A) M + N.
B) M – N.
C) M.
D) N.
E) None of the other choices is correct.
A) M + N.
Refer to Figure 3-2. Vector T as expressed in terms of vectors M and N is given by
A) M + N.
B) M – N.
C) M.
D) N.
E) None of the other choices is correct.
A) 2
What is the smallest number of vectors that can be added to give a zero resultant?
A) 2
B) 3
C) 4
D) 5
E) You cannot add vectors and obtain a zero resultant.
C) increase by a factor of 2.
Two vectors A and B are added together giving vector C. The magnitude of C is such that C = sqrt(A2+B2). If the magnitudes of both vectors A and B are doubled, the magnitude of vector C will
A) increase by a factor of 8.
B) increase by a factor of 4.
C) increase by a factor of 2.
D) increase by a factor of sqrt(2).
E) not change.
C) the three vectors must be in a plane.
If three vectors add up to a zero resultant it is correct to say that
A) it is impossible to find three vectors that add up to a zero resultant.
B) the three vectors must be co-linear.
C) the three vectors must be in a plane.
D) the three vectors must have the same magnitude.
E) the three vectors cannot have the same magnitude.
D) the resultant is zero.
Three vectors have equal magnitudes and make 120° with each other. We can say that
A) the magnitude of the resultant is one-third the magnitude of the component vectors.
B) the magnitude of the resultant is three times the magnitude of the component vectors.
C) the magnitude of the resultant is more than three times the magnitude of each component vector.
D) the resultant is zero.
E) the magnitude of the resultant is equal to the magnitude of the component vectors.
E) The resultant force is zero.
Refer to Figure 3-3. Three forces F1 = F2= F3= 70 N are acting on an object O as shown in the figure. Which one of the following statements is true regarding the resultant force acting over the object O?
A) The resultant force is 35 N.
B) The resultant force is 70 N.
C) The resultant force is 140 N.
D) The resultant force is 210 N.
E) The resultant force is zero.
D) 180°
What is the angle between the vectors A and -A when these vectors are drawn from a common origin?
A) 90°
B) 0°
C) 360°
D) 180°
E) 270°
D) Southward
A car travels along east and its velocity decreases. The acceleration of the car is in which of the following directions?
A) Eastward
B) Westward
C) Northward
D) Southward
E) Cannot be determined without additional information.
B) As a car travels eastward with its velocity is decreasing.
Under which of the following conditions would a car have a westward acceleration?
A) As a car travels eastward with its velocity is increasing.
B) As a car travels eastward with its velocity is decreasing.
C) As a car travels westward with its velocity is decreasing.
D) As a car travels westward with its velocity is constant.
E) As a car travels eastward with its velocity is constant.
D) zero.
A car travels along eastward with a constant velocity. The magnitude of the acceleration of the car is
A) decreasing.
B) increasing.
C) non-zero constant.
D) zero.
E) None of the other choices is correct.
A) the object is speeding up.
If the acceleration vector of an object is directed parallel to the velocity vector, then
A) the object is speeding up.
B) the object is slowing down.
C) the object is moving with a constant velocity.
D) the object is turning.
E) the object is at rest.
B) the object is slowing down.
If the acceleration vector of an object is directed anti-parallel to the velocity vector, then
A) the object is speeding up.
B) the object is slowing down.
C) the object is moving with a constant velocity.
D) the object is turning.
E) the object is at rest.
D) the object is turning.
If the acceleration of an object is always directed perpendicular to its velocity, then
A) the object is speeding up.
B) the object is slowing down.
C) the object is moving with a constant velocity.
D) the object is turning.
E) this situation would not be physically possible.
E) in a northwesterly direction.
You are trying to cross a river that flows due south with a strong current. You start out in your motorboat on the east bank desiring to reach the west bank directly west from your starting point. You should head your motorboat
A) due west.
B) due north.
C) due south.
D) in a southwesterly direction.
E) in a northwesterly direction.
C) the object is slowing down.
If the acceleration vector of an object is directed anti-parallel to the velocity vector,
A) the object is turning.
B) the object is speeding up.
C) the object is slowing down.
D) the object is not moving.
E) this situation would not be physically possible.
A) the object is turning.
If the acceleration vector of an object is directed perpendicular to the velocity vector,
A) the object is turning.
B) the object is speeding up.
C) the object is slowing down.
D) the object is not moving.
E) this situation would not be physically possible.
B) remains a non-zero constant.
For general projectile motion, the horizontal component of a projectile’s velocity
A) is zero.
B) remains a non-zero constant.
C) continuously increases.
D) continuously decreases.
E) any of the above, depending on position.
A) is zero.
For general projectile motion, the horizontal component of a projectile’s acceleration
A) is zero.
B) remains a non-zero constant.
C) continuously increases.
D) continuously decreases.
E) any of the above, depending on position.
B) remains a non-zero constant.
For general projectile motion, the vertical component of a projectile’s acceleration
A) is zero.
B) remains a non-zero constant.
C) continuously increases.
D) continuously decreases.
E) any of the above, depending on position.
C) continuously increases.
For a projectile launched horizontally, the vertical component of a projectile’s velocity
A) is zero.
B) remains a non-zero constant.
C) continuously increases.
D) continuously decreases.
E) any of the above, depending on position.
B) remains a non-zero constant.
For a projectile launched horizontally, the horizontal component of a projectile’s velocity
A) is zero.
B) remains a non-zero constant.
C) continuously increases.
D) continuously decreases.
E) any of the above, depending on position.
C) the ball is not acted upon by a force in the horizontal direction.
A ball rolls off the edge of a table. The horizontal component of the ball’s velocity remains constant during its entire trajectory because
A) the ball is not acted upon by any force.
B) the net force acting on the ball is zero.
C) the ball is not acted upon by a force in the horizontal direction.
D) the ball is not acted upon by a force in the vertical direction.
E) None of the other choices is correct.
B) the minimum speed needed to cross the crevasse decreases.
A mountain climber encounters a crevasse in an ice field. The opposite side of the crevasse is a height h lower, and is separated horizontally by a distance w. To cross the crevasse, the climber gets a running start and jumps in the horizontal direction. If the height of the crevasse increases but the width remains the same, then,
A) the minimum speed needed to cross the crevasse increases.
B) the minimum speed needed to cross the crevasse decreases.
C) the minimum speed needed to cross the crevasse stays the same
D) the minimum speed needed to cross the crevasse will depend on the mass of the mountain climber.
E) the minimum speed needed to cross the crevasse will depend on the weight of the mountain climber.
B) the splashdown speed of John is larger than that of James.
James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. When they reach the lake below,
A) the splashdown speed of James is larger than that of John.
B) the splashdown speed of John is larger than that of James.
C) they will both have the same splashdown speed.
D) the splashdown speed of James will always be 9.8 m/s larger than that of John.
E) the splashdown speed of John will always be 25 m/s larger than that of John.
C) James and John will reach the surface of the lake at the same time.
James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. Compare the time it takes each to reach the lake below.
A) James reaches the surface of the lake first.
B) John reaches the surface of the lake first.
C) James and John will reach the surface of the lake at the same time.
D) Cannot be determined without knowing the mass of both James and John.
E) Cannot be determined without knowing the weight of both James and John.
B) be over the bomb.
A pilot drops a bomb from a plane flying horizontally at a constant speed. Neglecting air resistance, when the bomb hits the ground the horizontal location of the plane will
A) be behind the bomb.
B) be over the bomb.
C) be in front of the bomb.
D) depend of the speed of the plane when the bomb was released.
E) depend of the mass of the bomb when it was released.
C) It is equal to its initial horizontal velocity.
A rock is thrown at some angle above the horizontal with a certain velocity. It reaches its highest point and starts falling down. What is the velocity of the rock at the highest point of its trajectory?
A) 0
B) 9.8 m/s
C) It is equal to its initial horizontal velocity.
D) It is equal to its initial vertical velocity.
E) It is equal to its initial velocity.
B) neither the ball’s velocity nor its acceleration is zero.
A student kicks a soccer ball in a high arc toward the opponent’s goal. At the highest point in its trajectory:
A) both velocity and acceleration of the soccer ball are zero.
B) neither the ball’s velocity nor its acceleration is zero.
C) the ball’s acceleration is zero but not its velocity.
D) the ball’s acceleration points upwards.
E) the ball’s velocity points downwards.
B) It is less than its initial speed.
When a football in a field goal attempt reaches its maximum height, how does its speed compare to its initial speed?
A) It is zero.
B) It is less than its initial speed.
C) It is equal to its initial speed.
D) It is greater than its initial speed.
E) Cannot be determined without additional information.
B) decreases.
A rock is thrown upwards at an angle of 40° with respect to the horizontal. As the rock is rising in its trajectory, the vertical component of its velocity
A) increases.
B) decreases.
C) remains the same.
D) is zero.
E) Cannot be determined without additional information.
C) remains the same.
A rock is thrown upwards at an angle of 40° with respect to the horizontal. As the rock is rising in its trajectory, the horizontal component of its velocity
A) increases.
B) decreases.
C) remains the same.
D) is zero.
E) Cannot be determined without additional information.
D) 0 m/s2
A projectile is launched with an initial velocity of 80 m/s at an angle of 30° above the horizontal. Neglecting air resistance, what is horizontal component of the projectile’s acceleration?
A) 80 m/s2
B) 40 m/s2
C) 9.8 m/s2
D) 0 m/s2
E) 4.9 m/s2
C) 9.8 m/s2.
A boy kicks a football with an initial velocity of 20 m/s at an angle of 25° above the horizontal. The magnitude of the acceleration of the ball while it is in flight is
A) 25 m/s2.
B) 20 m/s2.
C) 9.8 m/s2.
D) 8.4 m/s2.
E) 0 m/s2.
C) The vertical component of the velocity changes sign after the ball attains its maximum height.
An athlete throws a ball with a velocity of 40 m/s at an angle of 20° above the horizontal. Which of the following statements is true in this case?
A) The vertical component of the velocity remains constant.
B) The horizontal component of the velocity changes.
C) The vertical component of the velocity changes sign after the ball attains its maximum height.
D) The horizontal component of the velocity changes sign after the ball attains its maximum height.
E) None of the given choices is correct.
C) He should aim it above the monkey.
A monkey is sitting at the top of a tree 20 m high from the ground level. A person standing on the ground wants to feed the monkey. He uses a bow and arrow to launch the food to the monkey. If the monkey remains seated at the top of the tree, how should the person aim the arrow containing the food so that the monkey gets the food?
A) He should aim it at the monkey.
B) He should aim it below the monkey.
C) He should aim it above the monkey.
D) None of the other choices is correct.
A) He should aim it at the monkey.
A monkey is sitting at the top of a tree 20 m high from the ground level. A person standing on the ground wants to feed the monkey. He uses a bow and arrow to launch the food to the monkey. If the person knows that the monkey is going to drop from the tree at the same instant that the person launches the food, how should the person aim the arrow containing the food?
A) He should aim it at the monkey.
B) He should aim it below the monkey.
C) He should aim it above the monkey.
D) None of the other choices is correct.
D) 130 m/s
A bullet is fired from ground level with a speed of 150 m/s at an angle 30.0° above the horizontal at a location where g = 10.0 m/s2. What is the horizontal component of its velocity when it is at the highest point of its trajectory?
A) 0 m/s
B) 10 m/s
C) 75.0 m/s
D) 130 m/s
E) 150 m/s
A) 0 m/s
A bullet is fired from ground level with a speed of 150 m/s at an angle 30.0° above the horizontal at a location where g = 10.0 m/s2. What is the vertical component of its velocity when it is at the highest point of its trajectory?
A) 0 m/s
B) 10 m/s
C) 75.0 m/s
D) 130 m/s
E) 150 m/s
B) 45° above the horizontal
For which value of θ is the range of a projectile fired from ground level a maximum?
A) 30° above the horizontal
B) 45° above the horizontal
C) 55° above the horizontal
D) 60° above the horizontal
E) 90° above the horizontal
E) 90° above the horizontal
For which value of θ is the height of a projectile fired from ground level a maximum?
A) 30° above the horizontal
B) 45° above the horizontal
C) 55° above the horizontal
D) 60° above the horizontal
E) 90° above the horizontal
If the initial speed of a projectile is doubled.
A) Its range will be increased by 1.41.
B) Its range will double.
C) Its range will be decreased by a factor of two.
E) Its range will decrease by a factor of four.
D) The ranges of the two projectiles will be identical.
A projectile is launched with initial velocity v0 at an angle of 30° above the horizontal. If a second projectile is launched with the same initial velocity but at angle of 60° above the horizontal.
A) The range of the second projectile will be twice that of the first.
B) The range of the second projectile will be 1.41 that of the first.
C) The range of the second projectile will be one-half that of the first.
D) The ranges of the two projectiles will be identical.
E) It is impossible to compare the ranges of the two projectiles.
D) 60°
A ball is thrown with a velocity of 40 m/s at an angle of 30° above the horizontal and attains a certain range R. At what other angle will this ball attain the same range keeping its initial velocity the same?
A) 15°
B) 90°
C) 120°
D) 60°
E) All other angles will give different ranges.
C) the speed of the arrow is again v0.
Marcia uses a bow to shoot an arrow with initial velocity of magnitude v0 and at an angle θ above the horizontal. When the arrow returns to the same height from which it started,
A) the speed of the arrow is twice v0.
B) the speed of the arrow is 9.8 times larger than v0.
C) the speed of the arrow is again v0.
D) the speed of the arrow is sqrt(2)v0.
E) the speed of the arrow is v0/sqrt(2) .
C) Both snowballs will hit the ground with the same speed.
Mary and Debra stand on a snow-covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30° below the horizontal; Debra throws her snowball upward, at 30°. When the snowballs reach the ground below,
A) Debra’s snowball will have a higher speed than Mary’s.
B) Mary’s snowball will have a higher speed than Debra’s.
C) Both snowballs will hit the ground with the same speed.
D) Debra’s snowball never hits the ground since it is thrown upwards.
E) Mary’s snowball never hits the ground since it is thrown downwards.
A) Debra’s snowball will stay in the air longer than Mary’s.
Mary and Debra stand on a snow-covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30° below the horizontal; Debra throws her snowball upward, at 30°. When the snowballs reach the ground below,
A) Debra’s snowball will stay in the air longer than Mary’s.
B) Mary’s snowball will stay in the air longer than Debra’s.
C) Both snowballs will take the same amount of time to hit the ground.
D) Debra’s snowball never hits the ground since it is thrown upwards.
E) Mary’s snowball never hits the ground since it is thrown downwards.
C) It is equal to the magnitude of its initial velocity.
A rock is thrown from ground level at some angle above the horizontal with a certain velocity. It reaches its highest point and starts falling down. What is the magnitude of the velocity of the rock right before it hits the ground?
A) It is equal to its initial vertical velocity.
B) It is equal to its initial horizontal velocity.
C) It is equal to the magnitude of its initial velocity.
D) 0
E) Cannot be determined without additional information.
E) move with constant velocity.
In the absence of an external force, a moving object will
A) stop immediately.
B) slow down and eventually come to a stop.
C) move faster and faster.
D) move with constant velocity for a while and then slow to a stop.
E) move with constant velocity.
D) The net force on the object is zero.
An object is moving with constant velocity. Which of the following statements is true?
A) A constant force is being applied in the direction of motion.
B) A constant force is being applied in the direction opposite of motion.
C) There are no forces acting on the object.
D) The net force on the object is zero.
E) There is no frictional force acting on the object.
E) the force of air resistance is equal to the weight of the parachutist.
When a parachutist jumps from an airplane, he eventually reaches a constant speed, called the terminal velocity. This means that
A) the acceleration is equal to g.
B) the force of air resistance is equal to zero.
C) the effect of gravity has died down.
D) the effect of gravity increases as he becomes closer to the ground.
E) the force of air resistance is equal to the weight of the parachutist.
B) constant non-zero acceleration.
A constant net force acts on an object. Describe the motion of the object.
A) constant non-zero velocity.
B) constant non-zero acceleration.
C) increasing acceleration.
D) decreasing acceleration.
E) zero acceleration.
B) drop the hammer with the handle end down.
Imagine that the metal head of a hammer is loose. In order to get the hammerhead tight again you should
A) drop the hammer on its side from some given height.
B) drop the hammer with the handle end down.
C) drop the hammer with the head end down.
D) It makes no difference how you drop the hammer, the head will be tightened.
E) It makes no difference how you drop the hammer, the head will not be tightened.
D) one-fifth as that of object 1.
You apply the same force to two objects. Object 1 has mass M and object 2 has mass 5M. The acceleration of object 2 is
A) ten times that of object 1.
B) five times that of object 1.
C) the same as that of object 1.
D) one-fifth as that of object 1.
E) has no relation to that of object 1.
B) the force on the truck is equal to the force on the car.
A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the car. Since a lot of damage is done on the car
A) the force on the truck is greater then the force on the car.
B) the force on the truck is equal to the force on the car.
C) the force on the truck is smaller than the force on the car.
D) the truck did not slow down during the collision.
E) the car did not slow down during the collision.
D) 6000 N.
A truck is towing a car whose mass is one quarter that of the truck. The force exerted by the truck on the car is 6000 N. The force exerted by the car on the truck is
A) 1500 N.
B) 24000 N.
C) 3000 N.
D) 6000 N.
E) 12000 N.
B) exactly 2400 N.
golf club hits a golf ball with a force of 2400 N. The golf ball hits the club with a force
A) slightly less than 2400 N.
B) exactly 2400 N.
C) slightly more than 2400 N.
D) close to 0 N.
E) Cannot be determined without additional information.
C) larger when F is applied from the right.
In Figure 5-1, masses m1 and m2 are such that m1 > m2 and they lay on a level, frictionless surface. We can apply a horizontal force F either from the left or from the right. The contact force between masses m1 and m2 is
A) zero newtons.
B) larger when F is applied from the left.
C) larger when F is applied from the right.
D) the same in either case.
E) impossible to determine based on this data.
B) equal to the magnitude of F
A horse pulls a cart with force F. As a result of this force the cart accelerates with constant acceleration. What is the magnitude of the force that the cart exerts on the horse?
A) zero Newtons
B) equal to the magnitude of F
C) less than the magnitude of F
D) more than the magnitude of F
E) cannot be determined without additional information
C) a force equal to W
An object of weight W is in free-fall close to the surface of Earth. What is the force that the object exerts on Earth?
A) a force greater than W
B) a force less than W
C) a force equal to W
D) no force at all
E) cannot be determined without additional information
D) The object pulling upward on the Earth with force mg.
An object of mass m sits on a flat table. The Earth pulls on this object with force mg, which we will call the action force. What is the reaction force?
A) The table pushing up on the object with force mg.
B) The object pushing down on the table with force mg.
C) The table pushing down on the floor with force mg.
D) The object pulling upward on the Earth with force mg.
E) The table pulling upward on the Earth with force mg.
A) 1:2:3:4 . . .
A locomotive is pulling a number of identical wagons along a level track and accelerating. Friction is negligible. Starting from the last wagon, the ratio of the forces between adjacent wagons is
A) 1:2:3:4 . . .
B) 1:2:4:8 . . .
C) 1:3:5:7 . . .
D) 1:1/2:1/3:1/4 .
E) 1:1:1:1 . . .
C) g tan θ
A student uses a plumb bob to verify that the doorjamb in a car is vertical. As the car pulls away from a stop, the student observes that the string now makes an angle θ with the doorjamb. What is the acceleration of the car?
A) g sin θ
B) g cos θ
C) g tan θ
D) g θ
E) θ
A) equal to its weight.
A ball is thrown up into the air. Ignore air resistance. When it is rising and reaches half of its maximum height, the net force acting on it is
A) equal to its weight.
B) greater than its weight.
C) less than its weight, but not zero N.
D) zero N.
E) Cannot be determined without additional information.
D) The fireman continues to descend, but with constant speed.
A fireman is sliding down a fire pole. As he speeds up, he tightens his grip on the pole, thus increasing the vertical frictional force that the pole exerts on the fireman. When this force equals the weight of the fireman, what happens?
A) The fireman comes to a stop.
B) The fireman descends with slower and slower speed.
C) The fireman descends with a smaller acceleration.
D) The fireman continues to descend, but with constant speed.
E) Cannot be determined without additional information.
A) equal to the bucket’s weight.
A person is lowering a bucket into a well with a constant speed. The force exerted by the rope on the bucket is
A) equal to the bucket’s weight.
B) greater than the bucket’s weight.
C) less than the bucket’s weight, but not zero N.
D) zero N.
E) Cannot be determined without additional information.
A) equal to your true weight, mg.
You ride on an elevator that is moving downward with constant speed while standing on a bathroom scale. The reading on the scale is
A) equal to your true weight, mg.
B) more than your true weight, mg.
C) less than your true weight, mg.
D) could be more or less than your true weight, mg, depending on the value of the speed.
B) less than your true weight, mg.
You ride on an elevator that is moving with constant downward acceleration while standing on a bathroom scale. The reading on the scale is
A) equal to your true weight, mg.
B) less than your true weight, mg.
C) more than your true weight, mg.
D) could be more or less than your true weight, mg, depending on the magnitude of the
D) the component of the force exerted by a surface perpendicular to the surface
What does the word “normal” mean in the phrase “normal force”?
A) the force that is usually exerted by a surface
B) the total force exerted by a surface
C) the component of the force exerted by a surface parallel to the surface
D) the component of the force exerted by a surface perpendicular to the surface
E) the force is due to contact between two objects.
C) Mg cos θ.
A block of mass M slides down a frictionless plane inclined at an angle θ with the horizontal. The normal reaction force exerted by the plane on the block is
A) Mg.
B) Mg sin θ.
C) Mg cos θ.
D) Mg tan θ.
E) zero, since the plane is frictionless.
C) perpendicular to the plane.
A block of mass M slides down a frictionless plane inclined at an angle θ with the horizontal. The normal reaction force exerted by the plane on the block is directed
A) parallel to the plane in the same direction as the movement of the block.
B) parallel to the plane in the opposite direction as the movement of the block
C) perpendicular to the plane.
D) toward the center of the Earth.
E) toward the center of mass of the block.
D) toward the center of the Earth.
A block of mass M slides down a frictionless plane inclined at an angle θ with the horizontal. The gravitational force is directed
A) parallel to the plane in the same direction as the movement of the block.
B) parallel to the plane in the opposite direction as the movement of the block
C) perpendicular to the plane.
D) toward the center of the Earth.
E) toward the center of mass of the block.
B) decrease
An object rests on an inclined surface. If the inclination of the surface is made steeper, what does the normal force on the object do?
A) increase
B) decrease
C) stays the same
D) The normal force is zero N.
E) Cannot be determined without additional information.
E) The two objects reach the bottom of the incline at the same time.
Two objects have masses m and 5m, respectively. They both are placed side by side on a frictionless inclined plane and allowed to slide down from rest.
A) It takes the lighter object 5 times longer to reach the bottom of the incline than the heavier.
B) It takes the lighter object 10 times longer to reach the bottom of the incline than the heavier.
C) It takes the heavier object 5 times longer to reach the bottom of the incline than the lighter.
D) It takes the heavier object 10 times longer to reach the bottom of the incline than the lighter.
E) The two objects reach the bottom of the incline at the same time.
D) μk < μs.
Its more difficult to start moving a heavy carton from rest than it is to keep pushing it with constant velocity, because
A) The normal force is greater when the carton is at rest.
B) μs < μk. C) Initially, the normal force is not perpendicular to the applied force. D) μk < μs. E) μs = μk.
A) a frictional force is acting on it.
A packing crate slides down an inclined ramp at constant velocity. Thus we can deduce that
A) a frictional force is acting on it.
B) a net downward force is acting on it.
C) a net upward force is acting on it.
D) it is not acted on by appreciable normal force.
E) it is not acted on by appreciable gravitational force.
B) static
If a car slows down with the wheels rolling, is the frictional force between the tires and the ground kinetic or static?
A) kinetic
B) static
B) static
When a car goes around a curve, it has a tendency to skid outwards. Is the frictional force between the tires and the ground that keeps the car from skidding kinetic or static?
A) kinetic
B) static
A) forward
A flatbed truck is carrying a crate along a level road. The coefficient of static friction between the load and the bed is 0.40. The truck accelerates forward and the crate stays in its place on the truck bed. In what direction is the force that the bed exerts on the crate?
A) forward
B) backward
C) toward the center of the road
D) There is no frictional force because the crate does not move with respect to the bed.
E) There is not enough information to answer this question.
A) static friction.
As a car drives with its tires rolling freely without any slippage, the type of friction acting between the tires and the road is
A) static friction.
B) kinetic friction.
C) a combination of static and kinetic friction.
D) neither static nor kinetic friction, but some other type of friction.
E) It is impossible to tell what type of friction acts in this situation.
E) f = mg sinθ.
In Figure 6-1, the block of mass m is at rest on an inclined plane that makes an angle θ with the horizontal. The force of static friction f must be such that
A) f > mg.
B) f > mg cosθ.
C) f > mg sinθ.
D) f = mg cosθ.
E) f = mg sinθ.
D) F = mg cosθ.
In Figure 6-1, the block of mass m is at rest on an inclined plane that makes an angle θ with the horizontal. The normal force F acting on the block must be such that
A) F > mg.
B) F > mg cosθ.
C) F > mg sinθ.
D) F = mg cosθ.
E) F = mg sinθ.
A) exactly 9.81 N.
In Figure 6-2 the scale at left is attached to the ceiling and a mass of 1.00 kg hangs from it. It reads 9.81 N. The identical scale at the right is connected by perfect strings passing over perfect pulleys to two 1.00 kg masses hanging vertically at the end of the strings. The scale at right reads
A) exactly 9.81 N.
B) more than 9.81 N, but not quite twice as much.
C) less than 9.81 N.
D) exactly 19.62 N.
E) more than 19.62 N.
A) left
Compare the two situations shown in Figure 6-3. On the left (A), James is holding the rope and keeping the bucket at rest. On the right (B), James ties the rope to the bucket so that it keeps the bucket at rest. In both cases the bucket contains the same quantity of water. In what case is the tension in the rope higher?
A) left
B) right
C) It is the same in both cases.
D) We need more data to answer.
B) The sum of the two readings will be 32 kg.
A 16-kg fish is weighed with two spring scales, each of negligible weight, as shown in Figure 6-4. What will be the readings on the scales?
A) The bottom scale will read 16 kg, and the top scale will read zero.
B) The sum of the two readings will be 32 kg.
C) The top scale will read 16 kg, and the bottom scale will read zero.
D) Each scale will show a reading greater than zero and less than 16 kg, but the sum of the two readings will be 16 kg.
E) Each scale will read 8 kg.
C) The tension is smaller than m2 g.
Two masses, m1 and m2, are connected to each other as shown in Figure 6-5. Mass m1 slides without friction on the table surface. Both masses have acceleration of magnitude a as shown. How does the tension in the string compare to the weight, m2 g, of mass m2?
A) The tension is equal to m2 g.
B) The tension is larger than m2 g.
C) The tension is smaller than m2 g.
D) It depends on m1 being smaller than m2.
E) It depends on m1 being larger than m2.
A) with an acceleration less than g.
Two identical masses are attached by a light string that passes over a small pulley, as shown in Figure 6-6. The table and the pulley are frictionless. The masses are moving
A) with an acceleration less than g.
B) at constant speed.
C) with an acceleration greater than g.
D) with an acceleration equal to g.
E) with an acceleration that cannot be determined without additional information.
C) is directed toward the center of the circular path.
When an object experiences uniform circular motion, the direction of the acceleration is
A) in the same direction as the velocity vector.
B) in the opposite direction of the velocity vector.
C) is directed toward the center of the circular path.
D) is directed away from the center of the circular path.
E) depends on the speed of the object.
E) centripetal acceleration.
What type of acceleration does an object moving with constant speed in a circular path experience?
A) free fall.
B) terminal acceleration.
C) constant acceleration.
D) linear acceleration.
E) centripetal acceleration.
C) is directed toward the center of the circular path.
When an object experiences uniform circular motion, the direction of the net force is
A) in the same direction as the motion of the object.
B) in the opposite direction of the motion of the object.
C) is directed toward the center of the circular path.
D) is directed away from the center of the circular path.
E) is dependent on the speed of the object.
B) It is moving in a circle.
Consider a particle moving with constant speed such that its acceleration of constant magnitude is always perpendicular to its velocity.
A) It is moving in a straight line.
B) It is moving in a circle.
C) It is moving in a parabola.
D) It is moving in a hyperbola.
E) None of the above is definitely true all of the time.
A) larger in magnitude the smaller the radius of the circle.
For an object that travels at a fixed speed along a circular path, the acceleration of the object is
A) larger in magnitude the smaller the radius of the circle.
B) in the same direction as the velocity of the object.
C) smaller in magnitude the smaller the radius of the circle.
D) in the opposite direction of the velocity of the object.
E) zero.
A) g downward
A roller coaster car is on a track that forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at this point?
A) g downward
B) 0.5g downward
C) 2g downward
D) g upward
E) 2g upward
C) (rg)1/2
A roller coaster car (mass = M) is on a track that forms a circular loop (radius = r) in the vertical plane. If the car is to just maintain contact with the track at the top of the loop, what is the minimum value for its speed at that point?
A) rg
B) 2rg
C) (rg)1/2
D) (2rg)1/2
E) (0.5rg)1/2
C) to take the turn at a faster speed
The banking angle in a turn on the Olympic bobsled track is not constant, but increases upward from the horizontal. Coming around a turn, the bobsled team will intentionally “climb the wall,” then go lower coming out of the turn. Why do they do this?
A) to give the team better control, because they are able to see ahead of the turn
B) to prevent the bobsled from turning over
C) to take the turn at a faster speed
D) to take the turn at a slower speed
E) to reduce the g-force on them
E) No, since work involves a non-zero displacement.
Can work be done on a system if there is no motion?
A) Yes, since motion is only relative.
B) Yes, if the sum of the external forces is zero.
C) Yes, if an external force is acting on the system.
D) No, since a system which is not moving has no energy.
E) No, since work involves a non-zero displacement.
E) remains constant at zero.
If you push twice as hard against a stationary brick wall, the amount of work you do
B) doubles.
C) is cut in half.
D) remains constant but non-zero.
E) remains constant at zero.
D) 0 J
A person applies a constant force of 20 N to a rock of mass 1000 kg, for a total of 20 seconds. What is the work done by this person if the rock does not move at all by this applied force?
A) 1000 J
B) 2000 J
C) 20,000 J
D) 0 J
E) 400 J
A) 0 J
A person carries a mass of 10 kg and walks along the +x-axis for a distance of 100 m with a constant velocity of 2 m/s. What is the work done by this person?
A) 0 J
B) 20 J
C) 200 J
D) 1000 J
E) None of the other choices is correct.
D) 0 J
A person applies a constant force on an object of mass 20 kg that causes the object to move horizontally at a constant speed of 0.20 m/s through a distance of 0.80 m. What is the work done on the object?
A) 160 J
B) 10 J
C) 16 J
D) 0 J
E) Cannot be determined without knowing the magnitude of the applied force.
E) Neither of them do any work.
Two men, Joel and Jerry, push against a wall. Jerry stops after 10 min, while Joel is able to push for 5.0 min longer. Compare the work they do.
A) Joel does 75% more work than Jerry.
B) Joel does 50% more work than Jerry.
C) Jerry does 50% more work than Joel.
D) Joel does 25% more work than Jerry.
E) Neither of them do any work.
D) zero.
If you walk 5.0 m horizontally forward at a constant velocity carrying a 10 N object, the amount of work you do is
A) more than 50 J.
B) equal to 50 J.
C) less than 50 J, but more than 0 J.
D) zero.
B) negative.
A constant force is applied to an object that causes a certain displacement. If the angle between the force and the displacement is 135°, the work done by this force is
A) positive.
B) negative.
C) 0 J.
D) Cannot be determined without knowing the magnitude of the displacement.
E) Cannot be determined without knowing the magnitude of the applied force.
E) zero.
Work done by STATIC FRICTION is always
A) parallel to the surface.
B) perpendicular to the surface.
C) positive.
D) negative.
E) zero.
A) zero.
A simple pendulum, consisting of a mass m and a string of length L, swings upward, making an angle θ with the vertical. The work done by the tension force is
A) zero.
B) mgL.
C) mgL cos θ.
D) mgL sin θ.
E) mgL tan θ.
C) increases.
If the net work done on an object is positive, then the object’s kinetic energy
A) decreases.
B) remains the same.
C) increases.
D) is zero.
E) cannot be determined without knowing the object mass.
A) decreases.
If the net work done on an object is negative, then the object’s kinetic energy
A) decreases.
B) remains the same.
C) increases.
D) is zero.
E) cannot be determined without knowing the object mass.
B) remains the same.
If the net work done on an object is zero, then the object’s kinetic energy
A) decreases.
B) remains the same.
C) increases.
D) is zero.
E) cannot be determined without knowing the object mass.
C) 7.1 m/s
The ratio of the final kinetic energy to the initial kinetic energy of an object is one half. If the initial velocity of the object is 10 m/s, what is the final velocity?
A) 20 m/s
B) 10 m/s
C) 7.1 m/s
D) 2.7 m/s
E) 1.5 m/s
D) W1 = 3W2.
A car originally at rest has its speed increased to a value v in a period of 5 seconds. The work performed in this part of the motion is W1. Over the next 5 seconds the speed of the car is increased to 2v. In the second part of the motion the work performed is W2. It is correct to say that:
A) W1 = ½ W2.
B) W1 = W2.
C) W1 = 2W2.
D) W1 = 3W2.
E) W1 = 4W2.
B) 1/4
An object hits a wall and bounces back with half of its original speed. What is the ratio of the final kinetic energy to the initial kinetic energy?
A) 1/2
B) 1/4
C) 2
D) 4
E) 8
D) 1/2
John’s mass is half the mass of Jill. They both start walking and John moves twice as fast as Jill. What is the ratio of the kinetic energy of Jill to the kinetic energy of John?
A) 4
B) 2
C) 1
D) 1/2
E) 1/8
A) Kt = 16Kc.
A truck has four times the mass of a car and is moving with twice the speed of the car. If Kt and Kc refer to the kinetic energies of truck and car respectively, it is correct to say that
A) Kt = 16Kc.
B) Kt = 4Kc.
C) Kt = 2Kc.
D) Kt = Kc.
E) Kt = ½ Kc.
C) Both travel the same distance.
A 4.0 kg mass is moving with speed 2.0 m/s. A 1.0 kg mass is moving with speed 4.0 m/s. Both objects encounter the same constant braking force, and are brought to rest. Which object travels the greater distance before stopping?
A) the 4.0 kg mass
B) the 1.0 kg mass
C) Both travel the same distance.
D) Cannot be determined from the information given.
A) It would have skidded 4 times farther.
You slam on the brakes of your car in a panic, and skid a certain distance on a straight, level road. If you had been traveling twice as fast, what distance would the car have skidded, under the same conditions?
A) It would have skidded 4 times farther.
B) It would have skidded twice as far.
C) It would have skidded 1.4 times farther.
D) It would have skidded one half as far.
E) It is impossible to tell from the information given.
E) work.
On a force vs. position graph, the area under curve is a representation of
A) force.
B) position.
C) kinetic energy.
D) potential energy.
E) work.
B) the reciprocal of the spring constant.
Consider a plot of the displacement (x) vs. applied force (F) for an ideal elastic spring. The slope of the curve would be
A) the spring constant.
B) the reciprocal of the spring constant.
C) the acceleration of gravity.
D) the reciprocal of the acceleration of gravity.
E) the reciprocal of the displacement.
C) 4d
A block of mass m is pushed against a spring of spring constant k. The spring is compressed by a distance d, the block is then released. It is launched by the spring along a horizontal frictionless surface with a final speed v. A second block, this one having mass 4m is pushed against the same spring and released, gaining a final speed 2v. By what distance was the spring compressed in the second case?
A) d
B) 2d
C) 4d
D) 16d
E) 25d
C) 3v
A block of mass m is pushed against a spring of spring constant k. The spring is compressed by a distance d, the block is then released. It is launched by the spring along a horizontal frictionless surface with a final speed v. A second block, this one having mass 4m is pushed against the same spring by distance 6d and released. What is the final speed of the block in this case?
A) v
B) 2v
C) 3v
D) 4v
E) 5v
C) k must vary inversely with stretch.
Describe the type of spring “constant” needed to produce a constant restoring force like curve (a) in Figure 7-1. (straight line)
A) k must vary as the stretch squared.
B) k must be a real constant.
C) k must vary inversely with stretch.
D) k must vary proportional to stretch.
E) none of these
B) graph b (straight with negative slope)
Which of the graphs in Figure 7-1 illustrates Hooke’s Law?
A) graph a
B) graph b
C) graph c
D) graph d
E) none of these
D) graph d (curve with negative)
Which of the graphs in Figure 7-1 represents a spring which gets less stiff the more it is stretched?
A) graph a
B) graph b
C) graph c
D) graph d
E) none of these
C) Nm/s.
In the SI system of units, power has the same units as
A) Js/m.
B) Jm/s.
C) Nm/s.
D) W/m.
E) W/s.
E) four times Jack’s power output.
As compared to Jack, Jill does twice the work in half the time. Jill’s power output is
A) the same as Jack’s power output.
B) one-fourth as much as Jack’s power output.
C) one-half as much as Jack’s power output.
D) twice Jack’s power output.
E) four times Jack’s power output.
A) 12P
A force produces power P by doing work W in a time T. What power will be produced by a force that does six times as much work in half as much time?
A) 12P
B) 6P
C) P
D) 1/6P
E) 1/12P
D) 9 times yesterday’s power output.
Compared to yesterday, you did 3 times the work in one-third the time. To do so, your power output must have been
A) the same as yesterday’s power output.
B) one-third of yesterday’s power output.
C) 3 times yesterday’s power output.
D) 9 times yesterday’s power output.
E) 34 times yesterday’s power output.

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