AP Physics Questions

A toy doll and toy robot are standing on a frictionless surface facing each other. The doll has a mass 0.20 kg, and the robot has a mass of 0.30 kg. The robot pushes the doll with a force of 0.30 N. The magnitude of the acceleration of the robot is A) zero B) 0.60 m/s C) 1.0 m/s D) 1.5 m/s

C) 1.0 m/s

A rubber ball with mass 0.20 kg is dropped vertically from a height of 1.5 m above a floor. The ball bounces off the floor, and during the bounce 0.60 J of energy is dissipated. What is the maximum height of the ball after the bounce? A) 0.30 m B) 0.90 m C) 1.2 m D) 1.5 m

C) 1.2 m

The wheel on a vehicle has a rotational inertia of 2.0 kg⋅m2. At the instant the wheel has a counterclockwise angular velocity of 6.0 rad/s, an average counterclockwise torque of 5.0 N⋅m is applied, and continues for 4.0 s. What is the change in angular momentum of the wheel? a) 12 kg/m b) 16 kg/m c) 20 kg/m d) 32 kg/m

c) 20 kg/m

The figure above shows a uniform meterstick that is set on a fulcrum at its center. A force of magnitude F toward the bottom of the page is exerted on the meterstick at the position shown. At which of the labeled positions must an upward force of magnitude 2F be exerted on the meterstick to keep the meterstick in equilibrium?

point B

Two model cars, A and B, have the same mass...

same impulse

A wheel with radius 0.33 m and rotational inertia 2.0 kg/m spins on an axle with an initial angular speed of 3.0 rad/s. Friction in the axle exerts a torque on the wheel, causing the wheel to stop after 6.0 s. The average torque exerted on the wheel as it slows down has magnitude...

1.0 N(m)

Block A of mass 2.0 kg is released from rest at the top of a 3.6 m long plane inclined at an angle of 30 degrees, as shown in the figure above. After sliding on the horizontal surface, block A hits and sticks to block B, which is at rest and has mass 3.0 kg. Assume friction is negligible. The speed of the blocks after the collision is most nearly A) 2.4 m/s B) 3.2 m/s C) 3.8 m/s D) 6.0 m/s

2.4 m/s

An amusement park ride consists of a large wheel of radius R that rotates.... which of the following best describes the passenger's linear and angular velocity while passing point A?

angular velocity constant and linear velocity changing

A block is released from rest and slides down a frictionless ramp inclined at 30 degrees from the horizontal. When the block reaches the bottom, the Earth-block system has mechanical energy E0. The experiment is repeated, but now horizontal and vertical forces of magnitude F are exerted on the block as is slides, as shown above. When the block reaches the bottom, the mechanical energy of the Earth-block system... A) greater than E0 B) equal to E0 C) less than E0 D) cannot be determined without knowing F

A) greater than E0

A car and its driver, with a combined mass 600 kg, are moving along a straight, horizontal track when a malfunction causes the tires to stop rotating. The car skids to a halt at a constant acceleration, leaving skid marks on the road during the whole time it skids. Which two of the following measurements, taken together, would allow engineers to find the total mechanical energy dissipated during the skid? A) the length of skid marks B) the contact area of each tire with the track C) the coefficient of static friction between the tires and the track D) the coefficient of kinetic friction between the tires and the track

A) the length of skid marks D) the coefficient of kinetic friction between the tires and the track

A block of mass m is at rest on a rough incline, as shown in the figure above. Which of the following forces must have a magnitude equal to mg? Select two answers. A) the total force exerted on the block by the incline B) the normal force exerted on the block by the incline C) the force of friction exerted on the block by the incline D) the gravitational force exerted on Earth by the block

A) the total force exerted on the block by the incline D) the gravitational force exerted on Earth by the block

The figure above shows a rod that is fixes to a horizontal surface at pivot P. The rod is initially rotating without friction in the counterclockwise direction. At time t, three forces of equal magnitude are applied to the rod as shown. Which of the following is true about the angular speed and direction of rotation of the rod immediately after time t?

Angular speed = decreasing direction of rotation = counterclockwise

An amusement park ride consists of a large wheel of radius R that rotates..... while passing point A, the person releases a small rock of mass m, which falls to the ground without hitting anything A) 1/2mgR B) 1/2m(v^2+4gR) C) 1/2(4)mgR D) 1/2mv^2

B) 1/2m(v^2+4gR)

During an experiment a student records the net horizontal force exerted on an object moving in a straight line along a horizontal frictionless track. The graph shows the force as a function of time. Of the following, which is the best approximation of the magnitude of the change in momentum of the object between 0 s and 4 s? A) 20 kg/m B) 30 kg/m C) 40 kg/m D) The magnitude of the change in momentum cannot be determined without knowing the mass of the object.

B) 30 kg/m

A 12kg box sliding on a horizontal floor has an initial speed of 4m/s. The coefficient of friction between the box and the floor is 0.20. The box moves distance of 4.0 m in 2.0 s. The magnitude of the change in momentum of the box during this time is most nearly... A) 12 kg/m B) 48 kg/m C) 60 kg/m D) 96 kg/m

B) 48 kg/m

A cart is moving on a level track in the positive x-direction. A force acting parallel to the x-axis is exerted on the cart. The graph above shows the net force exerted on the cart as a function of displacement. As the cart travels from x=0 m to x=4 m, what is the net change in kinetic energy of the cart? A) Increase in 20 J B) Increase in 10 J C) Decrease in 20 J D) Decrease in 10 J

B) Increase in 10 J

The graph above represents the position of two identical carts on a straight horizontal track as a function of time. Which of the following statements about the magnitude of the momentum of the two-cart system's center of mass, Pcom, is true? A) Pcom is constant from t=0 to t=5 B) Pcom is smaller after t=2 s than it is before t=2 s C) Pcom is greater after t=2 s than it is before t=2 s D) Pcom increases at a constant rate from t=0 to t=5

B) Pcom is smaller after t=2 s than it is before t=2 s

A vehicle lands on Mars and explores its surface. The average gravitational field on the surface of Mars is 3.7 N(kg). The weight of the vehicle is defined as the gravitational force exerted on it. Which of the following statements are true about the vehicle's weight? Select two answers. A) The vehicle's weight was constant until it reached the surface of Mars B) The vehicle's weight increased while it was descending to the surface of Mars C) The vehicle's weight always equals the normal force exerted by Mars on the vehicle while it is landing D) The vehicle weighs less on the surface of Mars than on the surface of the Earth

B) The vehicle's weight increased while it was descending to the surface of Mars D) The vehicle weighs less on the surface of Mars than on the surface of the Earth

A projectile fired into the air explodes and splits into two halves of equal mass that hit the ground at the same time. If the projectile had not exploded, it would have landed at point X, which is a distance R to the right of the launch point. After the explosion, one of the halves lands at point Y, which is a distance 2R to the right of the launch point. If air resistance is negligible, where did the other half land? A) to the left of the launch point B) at the launch point C) between the launch point and point X D) Between points X and Y

B) at the launch point

Two blocks are on a horizontal, frictionless surface. Block A is moving with an initial velocity of v0 toward block B, which is stationary, as shown above. The two blocks collide, stick together, and move off with a velocity of v0/3. Which block, if either, has the greater mass? A) block A B) block B C) neither; their masses are equal D) cannot be determined

B) block B

A student uses a spring scale to exert a horizontal force on a block, pulling the block over a smooth floor. The student repeats the procedure several times, each time pulling the block from rest through a distance of 1.0 m. For which of the following graphs of force as a function of distance will the block be moving the fastest at the end of 1.0 m? *all answer choices are graphs* A) graph w/ straight horizontal line for 1.0 m B) graph w/ zig-zag line C) graph w/ constant increase (a normal line with slope of 1) D) graph w/ negative diagonal line and then a straight horizontal line

B) graph w/ zig-zag line

A block slides down an inclined plane in a classroom. Which of the following pieces of information are needed to determine whether the velocity of the block will be constant? Select two answers. A) the mass of the block B) the angle of the inclined plane C) the acceleration due to gravity in the classroom D) the coefficient of kinetic friction between the block and the inclined plane

B) the angle of the inclined plane D) the coefficient of kinetic friction between the block and the inclined plane

Two satellites are in circular orbits around Earth. Satellite A has speed vA. Satellite B has an orbital radius nine times that of satellite A. What is the speed of satellite B? A) vA/9 B) vA/3 C) 3vA D)9vA

B) vA/3

The graphs above show the magnitude F of a force exerted on an object as a function of the objects position x for two trials in an experiment. W1 and W2 are the work done on the object by force 1 and force 2, respectively. How do W1 and W2 compare, and why? A) W1>W2, because the maximum value of force 1 is greater than the maximum value of force 2 B) W1>W2, because the slope of force 1's graph increases, while the slope of force 2's graph decreases C) W1<W2, because the average value of force 1 is smaller than the average value of force 2 D) W1<W2, because at the midpoint, x=0.5 m, the value of force 1 is less than the value of force 2

C) W1<W2, because the average value of force 1 is smaller than the average value of force 2

The figure above shows a truck pulling three crates across a rough road. Which of the following shows the directions of all the horizontal forces acting on crate 2? *images showing the horizontal forces A) left: rope & right: cable B) left: rope, crate 3 & right: cable C) left: rope, crate 3, friction & right: cable D) (couldn't find answer)

C) left: rope, crate 3, friction & right: cable

The disk with a radius of 0.5 m is free to rotate around its center without friction. A string wrapped around the disk is pulled, as shown above, exerting a 2 N force tangent to the edge of the disk for 1 s. If the disk starts from rest, what is its angular speed after 1 s? A) 0 rad/s B) 1 rad/s C) 4 rad/s D) cannot be determined

Cannot be determined.

Three spheres, with masses indicated above, are initially far away from each other, and the gravitational potential energy of the three-sphere system is zero. The spheres are then brought together until each sphere is a distance r from the other two, as shown above. What is the new gravitational potential energy of the three-sphere system? A) -Gm^2/r B) -2Gm^2/r C) -4Gm^2/r D) -5Gm^2/r

D) -5Gm^2/r

An amusement park ride consists of a large wheel of radius R that rotates... what is the normal force exerted on the rider when passing point D? A) 0.2 Fg B) 0.8 Fg C) 1.0 Fg D) 1.2 Fg

D) 1.2 Fg

A small block slides without friction along a track toward a circular loop. The block has more than enough speed to remind firmly in contact with the track as it goes around the loop. The magnitude of the block's acceleration at the top of the loop is A) zero B) greater than zero but less than g C) equal to g D) greater than g

D) greater than g

Four forces exerted on a disk of radius R that is free to spin about its center, as shown above. The magnitudes are...

F2 and F4

A simple pendulum consists of a sphere tied to the end of negligible mass. The sphere is pulled back until the string is horizontal and then released from rest. Assume gravitational potential energy...

Less than 45 degrees

A meteoroid is in a circular orbit 600 km above the surface of a distant point. The planet has the same mass as Earth but has a radius that is 90% of Earth's. Does the planet exert a torque on the meteoroid with respect to the center of mass of the planet? Why or why not?

No, because the planet exerts a force on the meteoroid parallel to its position vector relative to the center of mass of the planet.

Steel sphere A of mass M is moving along a horizontal surface with constant speed v. Identical see sphere B is at rest and hangs on a string of length R attached to a support at point P, as shown in the figure above. The spheres collide, and as a result sphere A stops and sphere B swings a vertical height h before coming momentarily to rest. Knowing values for which of the following will allow determination of the angular impulse on sphere B with respect to P due to the collision? a) M and v only b) M, v, and h c) R and h d) R, M, and v

R, M, and v

A 4 kg object moving to the left collides with and sticks to a 3kg object moving to the right. Which of the following is true of the motion of the combined objects immediately after the collision?

The motion cannot be determined without knowing the speeds of the objects before the collision