Faster than the speed of light
A motorist wishes to travel 40 kilometers at an average speed of 40km/h. During the first 20 km an average speed of 40 km/s is maintained.during the next 1o kilometers however the motorist averages only 20km/h. To drive the last 10 kilometers and average 40 km/h the motorist must drive.
5N east
When a 10k g block is simultaneously pushed eastward with a force of 20 N and westward with 15N, the combination of these forces on the block is
is constant
When a ball increases in speed by the same amount each second its acceleration
either 11m.s or 5m/s depending on whether she runs in the same or opposite direction to the train’s motion
sophia runs along the aisle of a train car that moves at 8 m/s. Sophia’s speed relative to the floor is 3 m/s. Her speed relative to an observer at rest on the ground is
20 m
When you walk at an average speed of 4 m/s in 5 s you’ll cover a distance of
10 m/s^2
From the top of a cliff a ball is released from rest.
Neglect air resistance
After 10 seconds, its acceleration will be
Neglect air resistance
After 10 seconds, its acceleration will be
100 m/s
From the top of a cliff, a ball is released from rest.
Neglect air resistance.
After 10 seconds its speed will be
Neglect air resistance.
After 10 seconds its speed will be
500 M
From the top of a cliff, a ball is released from rest.
Neglect air resistance.
After 10 seconds, it will have fallen __ meters.
Neglect air resistance.
After 10 seconds, it will have fallen __ meters.
45m
A ball is thrown straight up with an initial speed of 30 m/s. How high does it go?
whether or not the surfaces move relative to each other
The force of friction between two surfaces can act
One half
A cart is pushed and undergoes a certain acceleration. If the force is held constant and the mass of the cart doubles, its acceleration would be
5 m/s^2
What is the acceleration of a 20kg pail of cement that is pulled upward with a force off 300N?
the highway pushing back on the wheels of the truck
The force that propels a heavy truck along a highway is provided by
4000 N
An axe is swung against a tree with a blow of 4000 N. The force that acts on the axe during this event is
…. Both the same.
Arnold and Suzie pull on opposite ends of a rope in a tug of war. The greater force exerted on the rope if by
80 N
The resultant of a 30N force and a 40N force cannot possibly be
Right side
Nellie hangs by one hand motionless from a clothesline as show. Which is on the verge of breaking.
10 times as much momentum
a 1kg ball has the same speed as a 10kg ball. Compared with the 1kg ball, the 10 kg ball has
less than before
A big fish coasts up to and swallows a small fish at rest. Right after lunch, the speed of the big fish is
2.5 km/h
Jock has a mass of 60kg and stands at rest on ice. Catches a 20 kg ball that is thrown to him at 10km/h. How fast does jocko and the ball move across the ice?
All strike with the same speed
Three baseballs are thrown from the cliff along paths A, B, and C. If their initial speeds are the same and air resistance is negligable. The ball that strikes the ground below with the greatest speed will follow path
lowest rotational inertia compared with the mass
For round objects rolling down an incline, the fastest objects are generally those with the
Solid ball
Which of these will roll down an incline fastest?
Earth
The Greek mathematician Eratosthenes made measurements to show the size of _______.
guides to thinking
Equations in Conceptual Physics are used mainly _______.
a synthesis of well-tested ideas
A theory in science is ______.
an agreement between trained investigators
A fact in science is ______.
wrong
A scientific hypothesis deemed valid must have a test for proving it ______.
Physics
Which of these is the most basic science?
applying scientific discoveries
Technology is a tool for ______.
one of many ways of making discoveries
The scientific method of Galileo and Bacon is ______.
Spiritual world
Religion is concerned mainly with the ______.
He discovered that a ball rolling down an incline and onto a horizontal surface would roll indefinitely.
What was the greatest discovery by Galileo during his inclined-plane experiments?
A non-zero net force
Newton said that something was needed to change the motion of an object. A clear reading of his first law tells us that what is needed is ______.
Zero
What is the net force on a crate sliding at an unchanging speed when pushed with a steady force of 75 N?
in your hand
If while riding in a smooth-riding train, you toss a coin upward, the coin will normally land ______.
He demonstrated that light and heavy objects gain the same amount of speed when falling.
What did Galileo demonstrate in his Leaning Tower of Pisa experiment?
10 N
What is the net force when a pair of 5-N forces simultaneously act in the same direction on an object?
Newton’s first law
Which of Newton’s laws does the equilibrium rule illustrate?
200N
How much support force acts on a 200-N girl standing on a weighing scale?
time
Galileo’s definition of speed was a breakthrough because he is acknowledged to be the first to consider ______.
direction
The difference between speed and velocity involves ______.
the same amount of speed each second
A ball rolling down an inclined plane each second picks up ______.
change by the same amount each second
if an object moves with constant acceleration its velocity must
100 m
A car accelerates at 2 meters/s/s. Assuming the car starts from rest, how far will it travel in 10 s?
none of the above
While a car travels around a circular track at a constant speed, its
An object covers a distance of 8 meters in the first second of travel, another 8 meters during the next second, and 8 meters again during the third second. Its acceleration in meters per second per second is approximately
110 km/h
While you are in a bus that moves at 100 km/h you walk from the back to the front at 10 km/h. What is your speed relative to the road outside?
instantaneous speed
A speedometer normally measures ______.
change in velocity per unit time
Which BEST describes what occurs when a body accelerates?
acceleration
Galileo discovered that when air resistance can be neglected, all objects fall with the same ______.
30m/s
A ball freely falling at 20 m/s will in the next second have a speed of ______.
acceleration
When we are talking about how quickly “how fast” changes, we’re talking about ______.
5m
In its first second of free fall, a dropped softball will fall a vertical distance of ______.
6m/s
Jogging Jake runs at 4 m/s along a train flatcar that moves at 10 m/s in the opposite direction. Jake’s speed relative to the ground is
6 m/s^2.
If a car increases its velocity from zero to 60 m/s in 10 seconds, its acceleration is
0m/s^2
An object covers a distance of 8 meters in the first second of travel, another 8 meters during the next second, and 8 meters again during the third second. Its acceleration is
the same
A rock dropped from a 5-m height accelerates at 10 m/s2 and strikes the ground 1 s later. If the rock is dropped from a height of 2.5 m, its acceleration of fall is
40m/s
At one instant a heavy object in air is moving upward at 50 meters per second. One second later its speed is approximately
10m/s
An apple falls from a tree and hits the ground 5 meters below with a speed of about
2 seconds
If a projectile is fired straight up at a speed of 10 m/s, the total time to return to its starting position is about
the same
A ball is thrown upwards and returns to the same location. Compared with its initial speed its speed when it returns is about
50 m/s
Neglecting air resistance, a ball projected straight upward so it remains in the air for 10 seconds needs an initial speed of
velocity
Whenever a net force acts on an object, there is a change in the object’s _______.
opposite to the direction of sliding
The direction of the force of friction on a sliding crate is _______.
weight
Which depends on gravity?
increases
As a skydiver gains speed in falling through the air, air resistance _______.
when the crate is pushed horizontally, whether sliding or not
A crate sits at rest on a factory floor. Friction between the crate and floor occurs _______.
Newton
The unit of mass is the kilogram, and the unit of weight is the _______.
inversely proportional to mass
In considering proportions, acceleration is _______.
when units of newtons and kilograms are used for force and mass
When does the proportion form of Newton’s second law take the form of an equation?
6N
A 10-N falling object encounters 4 N of air resistance. The net force on the object is
continue moving at 40 km/h
You drive your car at a constant 60 km/h along the highway. You apply the brakes until the car slows to 40 km/h. If at that moment you suddenly release the brakes, the car tends to
1500 kg
A tow truck exerts a force of 3000 N on a car, which then accelerates at 2 m/s2. What is the mass of the car?
the tissue paper has too little mass to exert as much force on the boxer’s fist
A boxer cannot exert much force on a piece of tissue paper suspended in air because _______.
the expelled gas pushing on the rocket
The force that propels a rocket is that provided by _______.
pushed harder on the floor while holding the rope
The team to win in a tug-of-war is the team that _______.
the magnitudes of both forces are the same
A Volkswagen Bug and a Volvo truck have a head-on collision. Which statement is true??
5N
A 7-N vector at an angle of 45° to the horizontal has a vertical component that is about _______.
are normally at right angles to each other
Force vector components for a sled pulled at an upward angle _______.
the wall pushes back
When you push against a wall, what pushes back?
friction between the apple and the floor
In the apple-pulling-the orange sequence in this chapter, what is the force that accelerates the system across the floor?
raquet
When hitting a tennis ball with your racquet, the force on the ball has the same magnitude as the force on the _______.
both his weight and the pull on his cage
When Monkey Mo dangles by a rope and pulls on his cage, each at different angle from the vertical, the rope tension will be greater than _______.
5 units
A vertical vector of 3 units combined with a horizontal vector of 4 units has a resultant of
lighter car
A pair of toy freight cars, one twice the mass of the other, fly apart when a compressed spring that joins them is released. Acceleration will be greater for the
5oo N
Joshua is attracted toward Earth by a 500-N gravitational force. The Earth is attracted toward Joshua with a force of
4m
Two people, one twice as massive as the other, attempt a tug-of-war with 12 meters of rope on frictionless ice. After a brief time, they meet. The heavier person slides a distance of
both the same
Arnold Strongman and Suzie Small each pull very hard on opposite ends of a rope in a tug-of-war. The greater force on the rope is exerted by
its mass times velocity is greater than that of the car
A slowly moving ship can have a greater momentum than a fast-moving racing car when _______.
product of force and time
The quantity that is called impulse can be measured by the _______.
impulse on the ball
Follow through is important in golf because it results in a greater _______.
her hand is made to bounce from the bricks
Cassy can get more force on the bricks she breaks with a blow of her bare hand when _______.
equal and opposite to the momentum of the fire cannonball
When a cannonball is fired from a cannon, the momentum of the recoiling cannon is momentarily _______.
whether the collision is elastic or inelastic
When two vehicles collide, momentum is conserved _______.
vectorally add up to equal the initial momentum of the firecracker
When a falling firecracker explodes, the momenta of its pieces _______.
force
A boxer rides with the punch so as to reduce _______.
transfers its momentum to the 8 ball
When a cue ball strikes an 8 ball head-on in a game of pool, the cue ball _______.
remains the same
When a big fish swims into an oncoming smaller fish and swallows it, the momentum of the two-fish system _______.
16kg
The mass of a ball moving at 3 m/s with a momentum of 48 kg m/s is
a corresponding change in momentum
It is correct to say that impulse is equal to
if the mass of the bullet equals the mass of the gun
A bullet is fired from a gun. The speed of the bullet will be about the same as the speed of the recoiling gun
identical to the force applied to the block
A karate expert executes a swift blow and breaks a cement block with her bare hand. The magnitude of the force experienced by her hand is
1/6 m/s
A 5-kg shark swimming at a speed of 1 m/s swallows an absent-minded 1-kg fish swimming toward it at 4 m/s. The speed of the shark after this meal is
1m/s
A 2-kg rifle that is suspended by strings fires a 0.01-kg bullet at 200 m/s. The recoil velocity of the rifle is about
all the same
A red car has a head-on collision with an approaching blue car with the same magnitude of momentum. A green car driving with the same momentum as the other cars collides with an enormously massive wall. Which of the three cars will experience the greatest impulse?
four times as much
The work that is done when twice the load is lifted twice the distance is _______.
the same
When one does twice the work in twice the time, the power expended is _______.
destroyed
Energy cannot be _______.
by four
When traveling twice as fast your kinetic energy is increased _______.
when the crate is pushed horizontally, whether sliding or not
A crate sits at rest on a factory floor. Friction between the crate and floor occurs _______.
Newton
The unit of mass is the kilogram, and the unit of weight is the _______.
inversely proportional to mass
In considering proportions, acceleration is _______.
When units of newtons and kilograms are used for force and mass
When does the proportion form of Newton’s second law take the form of an equation?
2m
A 2-kg box of taffy candy has 40 J of potential energy relative to the ground. Its height above the ground is
four times the kinetic energy
Two identical golf carts move at different speeds. The faster cart has twice the speed and therefore has
10N
About 40 J is required to push a crate 4 m across a floor. If the push is in the same direction as the motion of the crate, the force on the crate is about
bottom of its swing
The bob of a simple pendulum has its maximum kinetic energy at the
his potential energy is halved.
he has gained an amount of kinetic energy equal to half his initial potential energy.
his kinetic energy and potential energy are equal.
he has gained an amount of kinetic energy equal to half his initial potential energy.
his kinetic energy and potential energy are equal.
A circus diver drops from a high pole into water far below. When he is halfway down
greater than toward the center
The tangential speed on the outer edge of a rotating carousel is _______.
increased mass and increased distance to mass concentration
Rotational inertia about the midpoint of an object becomes greater with _______.
force and leverage distance
The torque exerted by a crowbar on an object increases with increased _______.
quadruples the tension in the string
When a rock tied to a string is whirled in a horizontal circle, doubling the speed _______.
a support force
Consider someone in a rotating space habitat. Rotational motion provides _______.
doubles
When the rotational speed of a rotating system doubles, its angular momentum _______.
the resultant forces and torques must both be zero.
For a system in mechanical equilibrium
1kg
A 1-kg rock is suspended from the tip of a meter stick at the 0-cm mark so that the meter stick balances like a seesaw when the fulcrum is at the 25-cm mark. From this information, what is the mass of the meter stick?
water
Which will roll down an incline in the shortest time, a can filled with water or the same can filled with ice?
increases
When a twirling ice skater brings her arms inward, her rotational speed
Terrestrial and cosmic laws
Isaac Newton synthesized _______.
the force quadruples
What happens to the force of attraction between two planets when the masses of both are doubled?
makes the units of measurement consistent
The constant G in Newton’s equation _______.
the force increases to one quarter
What happens to the force of attraction between two planets when the distance between them is doubled?
no support force
One’s weightlessness in space has most to do with _______.
Earth’s surface
Earth’s gravitational field is strongest at _______.
