To ask a question
According to the scientific method, why does a physicist make observations and collect data?
In the steps of the scientific method, what is the next step after formulating and objectively testing hypotheses?
To explain the basic features of a complex phenomena
Why do physicist use models?
manipulate a single variable or factor in an experiment
Which statement about models is not correct?
If you know a car’s acceleration, the information you must have to determine if the car’s velocity is increasing is the
The accelerations at A and B are each zero
In the graph on the right, how does the acceleration at A compare with the acceleration at B?
xi = +3 m
At the graph above, a toy car rolls from +3 to +5 m. Which of the following statements is true?
all of the above: the direction of the car’s final velocity, the magnitude of the car’s final velocity, and the displacement of the car
If you know the acceleration of a car and its initial velocity, you can predict which of the following?
measuring tool limitations/lack of precision, random errors, change in measurement
limitations to measurements
The traveler who takes a train to New York from Boston and the traveler who flies from Boston to New York will have the same displacements but opposite directions covered. The magnitudes will be different too as one will be positive and one will be negative.
distinguish between the displacement of a traveler who takes a train from New York to Boston and the displacement of ta traveler who flies from Boston to New York. Be sure to compare the magnitudes of the displacements.
B: II (b needs to be added to the tip of A, not the tail)
In the figure above, which diagram represents the vector addition, C = A + B?
D: IV (when subtracting vectors, you make the vector opposite)
In the figure above, which diagram represents vector subtraction, C = A – B
Multiplying or dividing vectors by scalars results in
C: 4 (each vector shown has a horizontal component except d2, which lies directly on the y axis)
How many displacement vectors shown in the figure above have horizontal components?
B: d1 and d3 (they have the same vertical distance)
Which displacement vectors shown in the figure above have vertical components that are equal?
D: -d5, x; -d5, y
(dy is in quadrant 4 which has both negative x and negative y values)
A hiker undergoes a displacement of d5 as shown in the figure above. A single displacement that would return the hiker to his starting point would have which of the following sets of components?
A vector that has components that lie along the -x-axis and the +y-axis is oriented at an angle A measured counterclockwise from the +x-axis. Which of the following ranges give the values of angle A?
X and Y have to be perpendicular to each other
The equation D=x^2+y^2 is valid only if x and y are magnitudes of vectors that have what orientations with respect to each other?
whenever a force causes a displacement of the object
Work is done on an object
A weightlifter holds a barbell overhead
In which of the following cases is no work done?
the component of the force that does work is I the direction opposite the displacement
if the sign of work is negative
The force of gravity does negative work when the worker lifts the bucket
A painter lifts a bucket of paint, carries it 5 m horizontally, then sets it back down. Which of the following is true?
No net work is done on the parachutist
A parachutist falls at a constant speed for 200m. Which of the following is true?
While lifting the block, the worker does positive work while gravity does negative, overall net work is positive. When resting in place for 3 seconds, the net work is zero, and when lowering it back down the worker does negative work and the gravity does positive work, overall net work is negative.
A construction worker lifts a heavy cinder block 1 m off the ground, holds it in place for 3 s, then sets it back down in the same place. Describe the forces doing work on the block and the net work on the block throughout this action
The kinetic energy increases by a factor of 4
how does the kinetic energy of an object change if the object’s speed doubles
The bocce ball has more kinetic energy, more strongly dependent on velocity and it has a greater impact
Which has more kinetic energy, a 4.0 kg bowling ball moving at 1.0 m/s or a 1.0 kg bocce ball moving at 4.0 m/s?
Sam and Rachel worked hard pushing the car
In which of the following sentences if work used in the everyday sense of the word?
A car decelerates while traveling on a flat stretch of road
In which of the following scenarios is work done?
Which of the following energy forms is associated with an object in motion?
kinetic energy involves motion, and potential energy involves position
The main difference between kinetic energy and potential energy is that
Elastic potential energy
Which form of energy is involved in weighing fruit on a spring scale?
a zero level
Gravitational potential energy is always measured in relation to
total energy is always conserved
which of the following is a true statement about the conservation of energy
The sun is composed mostly of hydrogen. The mass of the sun is 2.0×10^30 kg, and the mass of a hydrogen atom is 1.67×10^-27 kg. Estimate the number of atoms in the sun.
The radius of Earth is 6,370,000 m. Express this measurement in km in scientific notation with the correct number of significant digits.
One component is perpendicular to v; the other component equals v.
A boat travels directly across a river that has a downstream current, v. What is true about the perpendicular components of the boat’s velocity?
B. 606.9 km/h
A jet moving at 500.0 km/h due east is in a region where the wind is moving at 120.0 km/h in a direction 30.00° north of east. What is the speed of the aircraft relative to the ground?
A measure of the quantity of matter is
A change in the gravitational force acting on the an object will affect the object’s
What are the units of the coefficient of friction?
Which of the following is the tendency of an object to maintain its state of motion?
none of the above
A crate is released on a frictionless plan inclined at angle (theta) with respect to the horizontal. Which of the following relationships is true? (Assume that the x-axis is parallel to the surface of the incline.)
A car goes forward along a level road at constant velocity. The additional force needed to bring the car into equilibrium is
if a nonzero net force is acting on an object, then the object is definitely
which of the simultaneous equal but opposite forces resulting from the interaction of two objects?