AP Physics Final Exam Study Guide
An astronaut on the Moon simultaneously drops a feather and a hammer. The fact that they reach the surface at the same instant shows that
In the absence of air resistance all bodies at a given location fall with the same acceleration
A 7.0 N block sits on a rough surface. It is pulled by a force F1 at an angle θ from the horizontal as shown. Now the angle θ is increased, while the magnitude of the F1 remains the same. Which of the following is correct about the horizontal component of F1?
It decreases
The motion of an object moving along a straight line is descried by the graph of velocity v versus time t shown. Which of the following is true about the speed of the object during the time interval from zero to 8s?
It first decreases and then increases
A rock is thrown straight up from the earth's surface. Which one of the following statements concerning the net force acting on the rock at the top of its path is true?
It is equal to the weight of the rock.
The motion of an object moving along a straight line is descried by the graph of velocity v versus time t shown. Which of the following is true about the acceleration of the object during the time interval from 0 to 8 s?
It remains the same
A block of mass 10 kg moves from position A to position B shown in the figure above. The speed of the block is 10 m/s at A and 4.0 m/s at B. The work done by friction on the block as it moves from A to B is most nearly a. -280 J b. -220 J c. -200 J d. 0 J
b. -220 J
A 2-newton force applied to a 2-kilogram object causes it to move in a straight line 2 meters during an interval of 2 seconds. The object gains kinetic energy K during this interval. In which of the following cases will the object gain the same kinetic energy K? a. A 4-newton force is applied to a 1-kilogram object for 1 second. b. A 4-newton force is applied to a 1-kilogram object across 1 meter. c. A 4-newton force is applied to a 1-kilogram object for 4 seconds. d. A 4-newton force is applied to a 1-kilogram object across 4 meters.
b. A 4-newton force is applied to a 1-kilogram object across 1 meter.
A block falls onto a vertical spring from a height h and compresses the spring a distance y. Air resistance and friction may be neglected. At the point of maximum compression, which of the following must be true? a. The speed of the block is maximum. b. The acceleration of the block is not zero. c. The potential energy of the block-Earth-spring system is zero. d. The kinetic energy of the block is maximum.
b. The acceleration of the block is not zero.
The velocity vs. time graph for the motion of a car on a straight track is shown in the diagram. The thick lines represent the velocity. Assume that the car starts at the origin x=0. At what time is the car at the greatest distance from the origin?
t=5s
The position as a function of time for two objects moving along a straight line is shown in the graph. At which of the following times do the two objects have the same velocity?
tc
Two people, one of mass 100 kg and the other of mass 50 kg, stand facing each other on an ice-covered (essentially frictionless) pond. If the heavier person pushes on the lighter one with a force F, then
the magnitude of the acceleration of the lighter person will be twice the magnitude of the acceleration of the heavier person
Two identical stars, a fixed distance D apart, resolve in a circle about their mutual center of mass, as shown above. Each star has mass M and speed v. G is the universal gravitational constant. Which of the following is a correct relationship among these quantities?
v^2 = GM/2D
The velocity of a projectile at launch has a horizontal component vh and a vertical component vv. Air resistance is negligible. When the projectile is at the highest point of its trajectory, which of the following shown the vertical and horizontal components of its velocity and the vertical component of its acceleration?
vertical velocity- 0 horizontal velocity- vh vertical acceleration- g
An object on an inclined plane has a weight of 10 N. Which of the following gives the correct components of this wieght for the coordinate axes shown in the figure above, in which the y-axis is perpendicular to the incline's surface while the x-axis is parallel to the inclined surface?
x-component- +6 y-component- -8
When the net force that acts on a hockey puck is 10 N, the puck accelerates at a rate of 50 m/s^2. Determine the mass of the puck.
0.2 kg
A horizontal force F is used to pull a 5-kg block across a floor at a constant speed of 3 m/s. The frictional force between the block and the floor is 10N. What is the value of the coefficient of kinetic friction, μk?
0.20
The motion of an object moving along a straight line is descried by the graph of velocity v versus time t shown. What is the net displacement of the object for the time interval from 0 to 8 s?
0m
The accompanying graph describes the motion of a toy car across the floor for 10 seconds. What is the acceleration of the toy car at t=4s?
1 m/s^2
A tennis ball is shot vertically upward in an evacuated chamber (no air) with an initial speed of 20.0 m/s at time t = 0 s. Determine the velocity of the ball at t = 3.00 seconds.
10 m/s downward
A force F of 30 N accelerates three blocks of mass m1 = 10 kg, m2 = 20 kg, and m3 = 30 kg as shown. What is the tension in the cord connecting block two and block three?
15 N
The inclined plane in the figure above has the two sections of equal length and the different roughness. The dashed line shows where section 1 ends and section 2 begins. A block of mass M is placed at different locations on the incline. The coefficients of kinetic and static friction between the block and the plane are shown in the table below. If the block is sliding up section 2, what is the magnitude of the force of friction that is exerted on the block by the incline?
2 μk Mg cos θ
The figure shows the forces exerted on a block that is sliding on a horizontal surface: the gravitational force of 40 N, the 40 N normal force exerted by the surface, and a frictional force exerted to the left. The coefficient of friction between the block and the surface is 0.20. Th acceleration of the block is most nearly
2.0 m/s^2 to the left
A car is stopped at a red traffic light. When the light turns to green, the car has a constant acceleration and crosses the 9.10-m intersection in 2.47 s. What is the magnitude of the car's acceleration?
2.98 m/s^2
A tennis ball is shot vertically upward in an evacuated chamber (no air) with an initial speed of 20.0 m/s at time t = 0 s. How high does the ball rise?
20 m
Water drips from rest from a leaf that is 20 meters above the ground. Neglecting air resistance, what is the speed of each water drop when it hits the ground?
20 m/s
A ball of mass m is fastened to a string. The ball swings at constant speed in a vertical circle of radius R with the other end of the string held fixed. Neglecting air resistance, what is the difference between the string's tension at the bottom of the circle and at the top of the circle?
2mg
A ball traveling at a speed vo rolls off a desk and lands at a horizontal distance xo away from the desk, as shown in the figure. The ball is then rolled off the same desk at a spend of 3vo. At what horizontal distance will the ball land from the table?
3xo
A cart is initially moving at 0.5 m/s along a track. The cart comes to rest after traveling 1 m. The experiment is repeated on the same track, but now the cart is initially moving at 1 m/s. How far does the cart travel before coming to rest?
4 m
A person weighting 800 newtons on Earth travels to another planet with twice the mass and twice the radius of Earth. The person's weight on this other planet is most nearly
400 N
Two groups of five men each are engaged in a tug-of-war, each man pulling with a force of 900 N. If the rope does not move, the tension in it is
4500
Mars has a mass 1/10 that of Earth and a diameter 1/2 that of Earth. The acceleration of a falling body near the surface of Mars is most nearly
4m/s^2
The velocity vs. time graph for the motion of a car on a straight track is shown in the diagram. The thick lines represent the velocity. Assume that the car starts at the origin x=0. What is the average speed of the car for the 10 second interval?
5.00 m/s
The accompanying graph describes the motion of a toy car across the floor for 10 seconds. What was the total displacement of the toy car for the entire 10 second interval shown?
6.5 meters
The acceleration due to gravity on the moon is only about 1/6 of that on earth. An astronaut whose weight on earth is 600N travels to the lunar surface. His mass measured on the moon is
60 kg
Inside a washing machine, the radius of the cylinder where the clothes sit is 0.50 m. In one of its settings the machine spins the cylinder at 2.0 revolutions per second. What is the acceleration of an item of clothing?
70 m/s^2
The motion of a circus clown on a unicycle moving in a straight line is shown in the graph below. After 12 seconds, how far is the clown from her original starting point?
74 m
A car starts from rest and accelerates at a constant rate in a straight line. In the first second the car covers a distance of 2.0 meters. How fast will the car be moving at the end of the second second?
8.0 m/s
Two iron spheres separated by some distance have a minute gravitational attraction, F. If the spheres are moved to one half their original separation and allowed to rust so that the mass of each sphere increases 41%, what would be the resulting gravitational force?
8F
Ball A is dropped from rest from a window. At the same instant, ball B is thrown downward; and ball C is thrown upward from the same window. Which statement concerning the balls is necessarily true if air resistance is neglected?
All three balls have the same acceleration at any instant
A child sits at the outer edge of a merry-go-round that rotates at constant speed. The child releases a ball at point P, shown in the view from above. As seen by a person who is at rest with respect to the Earth and looking down from above the merry-go-round, the path followed by the ball is shown by the arrow in which of the following?
Arrow goes straight up
The horizontal turntable shown above rotates at a constant rate. As viewed from above, a coin on the turntable moves counterclockwise in a circle as shown. Which of the following vectors best represents the direction of the frictional force exerted on the goin by the turntable when the coin is in the position shown?
Arrow pointing straight down
Consider the motion of an object given by the position vs. time graph shown. For what time(s) is the speed of the object greatest?
At time t=4.0s
The diagrams show four identical cars set at rest at the very top of four different inclines. The vertical and horizontal lengths of the inclines are shown in each diagram. In which two cases will a car have the greatest speed at the bottom of the incline? Select two answers.
C and D both have height of 4m
Consider a cart of mass M that can roll on frictionless bearings. In which of the following cases will the normal force acting on the cart be less than the cart's weight? Select TWO answers
Cart accelerates down an incline plane Cart pulled by a string that makes an angle above the vertical
The diagram represents a constant force F acting on a box located on a frictionless horizontal surface. As the angle θ between the force and the horizontal increases, the acceleration of the box will
Decrease
The stacks of boxes shown in the figure above are inside an elevator that is moving upward. The masses of the boxes are given in terms of the mass M of the lightest box, Assume the elevator is moving at constant speed and consider the bottom box in the stack that has two boxes of mass 2M. Let F floor be the force exerted by the floor on the box, Fg be the force exerted by the gravity on the box, and F box be the force exerted by the top box on the bottom box. Which of the following best represents the forces exerted on the bottom box?
F-floor up F-g down F-box down
Which of the following graphs could correctly represent the motion of an object moving with a constant speed in a straight line?
Graphs 1 and IV only
The stacks of boxes shown in the figure above are inside an elevator that is moving upward. The masses of the boxes are given in terms of the mass M of the lightest box, Assume the elevator has upward acceleration a and consider the tack that has two boxes of mass M. What is the magnitude of the force exerted on the top box by the bottom box?
M (a+g)
A force accelerates a body of mass M. The same force applied to a second body produces three times the acceleration. What is the mass of the second body?
M/3
A block of mass M is initially at rest on top of a block of mass m. also at rest. There is friction between the two blocks such that the coefficient of kinetic friction is μ. There is no friction between block m and the table. At time t=0, a constant force F is applied to block m directed tot he right. Once the force is applied, block M slides on top of block m. Let a1 be the acceleration of M after time t=0. Which of the following equations correctly relates the acceleration to the other quantities given?
Ma1=μMg
Two projectiles are launched with the same initial speed from the same location, one at 30 degree angle and the other at a 60 degree angle with the horizontal. They land at the same height at which they were launched. If air resistance is negligible, how do the projectiles' respective maximum heights, H30 and H60, and times in the air, T30 and T60 compare with each other?
Maximum height - H30<H60 Time in Air - T30<T60
The inclined plane in the figure above has the two sections of equal length and the different roughness. The dashed line shows where section 1 ends and section 2 begins. A block of mass M is placed at different locations on the incline. The coefficients of kinetic and static friction between the block and the plane are shown in the table below. If the block is at rest on section 1 of the incline, what is the magnitude of the force of static friction exerted on the block by the incline?
Mg sin θ
Two objects, X and Y, accelerate from the rest with the same constant acceleration. Object X accelerates for twice the time as object Y. Which of the following is true of these objects at the end of their respective periods of acceleration?
Object X has traveled four times as far as object Y
Block A hangs from a light string that passes over a light pulley and is attached to block B, which is on a level horizontal frictionless table, ash shown. Students are to determine the mass of block B from the motion of the two-block system after it is released from the rest. They plan to measure the time block A takes to reach the floor. The students mush also take which of the following measurements to determine the mass of block B?
Only the mass of block A and the distance block A falls to reach the floor
A 1 kg block sits on an incline plane, as shown above. Which of the following arrows best represents the direction of normal force acting on the block?
Perpendicular to the ramp- pointing up and to the right
The graph of position vs. time for an object moving along a straight line is given. During the time shown on the graph, the speed and acceleration of the object will have which of the following characteristics?
Speed - Constant but not zero Acceleration - Zero
Planet 1 orbits Star 1 and Planet 2 orbits Star 2 in circular orbits of the same radius. However, the orbital period of Planet 1 is longer than the orbital period of planet 2. What could explain this?
Star 1 has less mass than Star 2
Two boxes are connected to each other by a string shown in the figure. The 10-N box slides without friction on the horizontal table surface. The pulley is ideal and the string has negligible mass. What is true about the tension T in the string?
T < 30 N
How does the acceleration at A compare with the acceleration at B?
The acceleration at A and B are each zero
Consider the figure above which shows a ball that is projected and follows a parabolic path. Point Y is the highest point on the path, and air resistance is negligible. Which of the following best shows the direction of the acceleration of the ball at point X?
arrow pointing straight downward
A ball is shot and becomes a projectile over the course of a 3-second interval. The graphs show the horizontal velocity vx and vertical velocity vy of the ball as functions of time. Which of the following gives aa verbal description of the ball's motion that corresponds to the graphs?
The ball is shot at a 45 degree angle from the floor of a room and strikes the ceiling.
A block rests on an incline that makes an angle θ with the horizontal. The block remains at rest as θ is slowly increased. What happens to the magnitudes of the normal force and the static friction force of the incline on the block?
The friction force increases while the normal force decreases.
Each of the figures above shows a tractor attached to an object. The tractor exerts the same constant force F on each object in every case. Which of the following is a true statement about an object and the relative magnitudes of the force exerted by the object on the tractor?
The magnitude of the force exerted by each object on the tractor is equal, because the tractor exerts an equal force on each object
A student conducts an experiment related to the Newton's second law. The collected data are displayed on the graph above. From this graph, what conclusion can the student make?
The mass of the system in question was constant
A ladder at rest is leaning against a mall at an angle. Which of the following forces must have the same magnitude as the frictional force exerted on the ladder by the floor?
The normal force exerted on the ladder by the wall
A child whirls a ball at the end of a rope, in a uniform circular motion. Which of the following statements is true? Select TWO answers
The speed of the ball is constant The magnitude of the ball's acceleration is constant
The stacks of boxes shown in the figure above are inside an elevator that is moving upward. The masses of the boxes are given in terms of the mass M of the lightest box, How does the magnitude of the force exerted by the top box on the bottom box compare with magnitude of the fore exerted by the bottom box on the top box for each of the stacks?
The two magnitudes are always equal in each of the stacks
A tennis ball is thrown upward at an angle from point A. It follows a parabolic trajectory and hits the ground at point D. At the instant shown, the ball is at point B. Point C represents the highest position of the ball above the ground. How do the x and y components of the velocity vector of the ball compare at the points B and C?
The x component are the same; the y component at C is 0 m/s
A car initially travels north and then turns to the left along a circular curve. This causes a package on the seat of the car to slide toward the right of the car. Which of the following is true of the net force on the package while it is sliding?
There is not enough force directed toward the center of the circle to keep the package from sliding
A ball attached to a string is whirled around in a horizontal circle having a radius R. If the radius of the circle is changed to 4R and the same centripetal force is applied by the string, the new speed of the ball is which of the following?
Twice the original speed
A block of weight W is pushed and held against a rough, fixed wall by a force P. The frictional force between the block and the surface is f, and the normal force is N. Which of the following is equal to the magnitude of the force of friction acting on the block?
W
A crate of weight W on a horizontal floor is pushed by a force F as shwon in the figure. The normal force from the floor on the crate is given by
W + F sin θ
A block of mass M slides down a plane inclined at an angle of 3o degrees to the horizontal as shown. Which of the following diagrams shows the sources and directions of the three forces acting on the block in any real situation?
Weight pointing down Friction pointing up and to the left (parallel to the surface) Normal pointing up and to the right (perpendicular to the surface)
Consider a region where the gravitational field of 10 N/kg is uniform and points in the -y direction. A 2 kg object at the origin O is moved along the path y = x to point A (x = 2 m, y = 4 m) . The object is then moved along the path ( x − 2) = (y − 4)^2 to the point B (x = 6 m, y = 6 m), as shown. How much work is done by gravity as the object is moved from O to B? a. - 120 J b. - 80 J c. 0 J d. 80 J e. 120 J
a. - 120 J
An object is subject to a force F that varies with its position. When the object is taken along any path so that the final position is the same as the intial position, the net amount of work done by F is zero. Which of the following best describes the force F? a. Conservative b. Dissipative c. Centripetal d. Frictional
a. Conservative
A race car going around a flat, unbanked circular track gradually increases speed as it completes one full trip around the track. Which of the following can explain why the car gains speed? a. Energy stored in the fuel is converted to mechanical energy. b. A component of the frictional force exerted by the ground on the tires is directed toward the center of the circle. c. A component of the frictional force exerted by the ground on the tires is in the direction of motion. d. The car's velocity and acceleration are perpendicular.
a. Energy stored in the fuel is converted to mechanical energy. c. A component of the frictional force exerted by the ground on the tires is in the direction of motion.
An object is moving in the positive x-direction while a net force directed along the x-axis is exerted on the object. The figure shows the force as a function of position. What is the net work done on the object over the distance shown? a. F d b. 1.5F d c. 2F d d. 4F d
a. F d
The graph shows elongation as a function of the applied force for two springs, A and B. Compared to the spring constant for spring A, the spring constant for spring B is a. Larger b. Smaller c. Answer depends on the length of the each spring d. Answer depends on the force applied to each spring
a. larger
A rock is lifted for a certain time by a force F that is greater in magnitude than the rock's weight W. The change in kinetic energy of the rock during this time is equal to the a. work done by the net force (F - W). b. work done by F alone. c. work done by W alone. d. difference in the potential energy of the rock-Earth system before and after this time.
a. work done by the net force (F - W).
A time t=0, a projectile is launched from the top of a cliff at an angle of 30 degree below the horizontal. Which of the following pairs of graphs best represents the horizontal displacement x and the vertical velocity component v vert of the projectile as a function of time t?
a.) horizontal displacement - start at origin and go up at a positive slope vertical velocity component - start under the origin and go down at a negative slope
As the power of a machine is increased by a factor of 4, the time required to move an object a fixed distance against gravity a.Decreases by a factor of 4 b. Decreases by a factor of 2 c. Increases by a factor of 2 d. Increases by a factor of 4
a.Decreases by a factor of 4
Two artificial statellites, 1 and 2, orbit the Earth in circular orbits having radii R1 and R2, respectively, as shown above. If R2 = 2R1, the accelerations a2 and a1 of the two satallites are related by which of the following?
a2 = a1/4
The diagram below shows a 50 kg crate on a frictionless plane at angle θ to the horizontal. The crate is pushed at constant speed up the incline from point A to point B by a force F. If angle θ were increased but the vertical positions of the two points remain the same, what would be the effect on the magnitude of force F and the total work W done on the crate as it is moved from A to B? a. W would remain the same and the magnitude of F would decrease. b. W would remain the same and the magnitude of F would increase. c. W would increase and the magnitude of F would decrease. d. W would increase and the magnitude of F would increase.
b. W would remain the same and the magnitude of F would increase.
A weight lifter lifts a mass m at constant speed to a height h in time t. What is the average power output of the weight lifter? a. mg b. mgh/t c. mgh d. mght
b. mgh/t
When an object is moved from rest at point A to rest at point B in a gravitational field, the net work done by the field depends on the mass of the object and a. the path taken between A and B only b. the positions of A and B only c. the velocity of the object as it moves between A and B d. the nature of the external force moving the object from A to B
b. the positions of A and B only
A child slides from rest down slides A and B shown above. The slides are the same height, and the coefficient of friction between the slides and the child is the same. Which of the following compares the change ΔK in the kinetic energy of the child and the change ΔU in the potential energy of the child-Earth system for the two slides? a. ΔKA = ΔKB ; ΔUA = ΔUB b. ΔKA > ΔKB ; ΔUA = ΔUB c. ΔKA < ΔKB ; ΔUA > ΔUB d. ΔKA > ΔKB ; ΔUA > ΔUB
b. ΔKA > ΔKB ; ΔUA = ΔUB
In which of the following situations is the kinetic energy of the object decreasing? a. A sphere is dropped from a building. b. A satellite is moving in a circular orbit around Earth. c. A baseball is heading upward after being thrown at an angle. d. An elevator is moving upward at a constant velocity.
c. A baseball is heading upward after being thrown at an angle.
A racing car is moving around the circular track o radius 300 meters shown above. At the instant when the car's velocity is directed due east, is acceleration is directed due south and has a magnitude of 3 meters per second squared. When viewed from above the car is moving
clockwise at 30 m/s
A block on a horizontal surface of negligible friction is placed in contact with an ideal spring, as shown. The block is moved to the left so that the spring is compressed a distance x from equilibrium and then released from rest. The block has kinetic energy K1 when it separates from the spring. When the spring is compressed a distance 2x and the block is released from rest, the kinetic energy of the block when it separates from the spring is a. K1 b. square root of 2K1 c. 2k1 d. 4k1
d. 4k1
A ball is thrown vertically upward with an initial speed of exactly 15 meters per second. If air resistance is NOT negligible, the kinetic energy of the ball when it has fallen back to the point from which it was thrown will be a. Exactly one-half of its initial kinetic energy b. Exactly the same as the ball-Earth potential energy at the top of its rise c. Greater than its initial kinetic energy d. Less than its initial kinetic energy
d. Less than its initial kinetic energy
Some students want to calculate the work done by friction as an object with unknown mass moves along a straight line on a rough horizontal surface. The students have a force probe, a meterstick, and a stopwatch. Which of the following will allow the students to take the measurements needed to calculate the work done by friction? a. Pulling the block at an unknown constant acceleration with the force probe for a measured time b. Pulling the block at an unknown constant speed with the force probe for a measured time c. Pulling the block at an unknown constant acceleration with the force probe for a measured distance d. Pulling the block at an unknown constant speed with the force probe for a measured distance
d. Pulling the block at an unknown constant speed with the force probe for a measured distance
The spring expands upward and throws the block vertically back into the air. Which of the following is true after the block leaves the spring? a. The block has no kinetic energy. b. The block-spring-Earth system has no potential energy. c. The block reaches its maximum acceleration just after leaving the spring. d. The block will rise to the height from which it was dropped.
d. The block will rise to the height from which it was dropped.
A box of mass m is initially at rest at the top of a ramp that is at an angle θ with the horizontal. The block is at a height h and length L from the bottom of the ramp. The block is released and slides down the ramp. The coefficient of kinetic friction between the block and the ramp is μ. What is the kinetic energy of the box at the bottom of the ramp? a. mgh b. μmgLcosθ c. mgh − μmghcosθ d. mgh − μmgLcosθ
d. mgh − μmgLcosθ
The graph shows the velocity v as a function of time t for an object moving in a straight line. Which of the following graphs shows the corresponding displacement x as a function of time t for the same time interval?
d.) graph increases steadily and continues to go up much more than others
In the diagram a cart starts from rest at ground level (point A). It is pulled up the inclined plane to the top at a constant speed where its kinetic energy is 30 J and the potential energy of the cart-Earth system is 20 J (point B). The friction force was 3.0 N. The length of the inclined plane is 5.0 m. What is the total work done in moving the object from A to B? a. 10 J b. 15 J c. 35 J d. 50 J e. 65 J
e. 65J
A box of mass m is released from rest at position 1 on the frictionless curved track shown. It slides a distance d along the track in time t to reach position 2, dropping a vertical distance h. Let v and a be the instantaneous speed and instantaneous acceleration, respectively, of the box at position 2. Which of the following equations is valid for this situation? a. h=vt b. h=1/2gt^2 c. d=1/2dt^2 d. v^2=2ad e. mgh=1/2mv^2
e. mgh=1/2mv^2
A 7.0 N block sits on a rough surface. It is pulled by a force F1 at an angle θ from the horizontal as shown. Which of the following describes the normal force on the block?
less than 7.0 N but not zero
Two boxes P and Q on a perfectly smooth horizontal surface are connected by a light horizontal cord. The mass of P is greater than that of Q. A horizontal force F is applied to box Q as shown in the figure, acceleration the bodies to the right. The magnitude of the force exerted by the connecting cord on body P is
less than F but not zero
Vector A has a magnitude A, direction θA, and components Ax and Ay, Vector B has a magnitude B, direction θB, and components Bx and By. if B=2A then which of the following is true?
θA = θB
A newly discovered planet has twice the mass of the Earth, but the acceleration due to gravity on the new planet's surface is exactly the same as the acceleration due to gravity on the Earth's surface. The radius of the new planet in terms of the radius R of Earth is
√2 R
