AP PHYSICS 1: UNIT 5 PROGRESS CHECK: MCQ
PART A & B QUESTIONS AND COMPLETE ANSWERS
Block X of mass M slides across a horizontal surface where friction is negligible. Block X collides with
block Y of mass 2M that is initially at rest, as shown in Figure 1. After the collision, both blocks slide
together with a speed vs , as shown in Figure 2. 9/2Mv^2
What is the speed of the center of mass of the two-block system immediately before the collision?
The speed is v.
How could a student verify that the collision under consideration is an inelastic collision for the two-
block system? By comparing the final kinetic energy of the system with the initial kinetic energy of
the system
Block X of mass M travels with a speed v0. Block Y of mass 2M travels with a speed 2v0. Both blocks
travel toward each other and collide. After the blocks collide, they separate so that the kinetic energy of
the system remains conserved. Which of the following equations for the conservation of momentum
could a student use to help determine the speed vf of each block after the collision?
m0v0−4m0v0=m0vXf+2m0vYf, because the two blocks initially travel in opposite directions, and
the blocks do not stick after the collision.
Block X and block Y travel toward each other along a horizontal surface with block X traveling in the
positive direction. Block X has a mass of 4kg and a speed of 2ms. Block Y has a mass of 1kg and a speed
of 1 ms. A completely inelastic collision occurs in which momentum is conserved. What is the
approximate speed of block X after the collision? 1.4 m/s
, Block X and block Y travel toward each other along a horizontal surface with block X traveling in the
positive direction. Block X has a mass of 2kg and a speed of 3m/s. Block Y has a mass of 1kg and a speed
of 3m/s. After the collision, block X travels in the horizontal direction with a speed of 1m/s in the
negative direction. What is the speed of block Y if the collision is elastic? 5 m/s
Cart X travels in the positive direction along a horizontal surface, and cart Y travels in the positive
direction. The carts collide, and a student collects data about the carts' velocities as a function of time
before, during, and after a collision, as shown. The masses of both objects are known. Which of the
following best indicates how the student should use the graph to determine whether the collision is
elastic or inelastic and provides a correct justification? Using the known mass and known velocity
for each cart to determine the kinetic energy of the system before and after the collision, because the
kinetic energy changes in an inelastic collision
In an experiment, two objects, Object X and Object Y, travel toward each other and collide. Data are
collected about each object before, during, and after the collision to create a graph that shows the
momenta of Object Xand Object Y as a function of time. How should a student use the data found on the
graph to verify the conservation of momentum? The vector sum of the momenta should be
compared, because momentum is a vector quantity.
A student must conduct an experiment to verify the conservation of momentum. Cart X and Cart Y travel
toward each other and eventually collide, as shown in the figure. The student has access to the two
carts, one mass balance, and two motion detectors. If the mass of each cart is known, how should the
student arrange one or both motion detectors so that the student can collect enough information about
the motion of the carts, in order to verify the conservation of momentum of the system? 2 motion
detectors outside the collision
A student conducts three experiments in which two carts, cart 1 and cart 2, travel toward each other and
collide. A graph of each cart's momentum as a function of time is shown above. In which experiment, if
PART A & B QUESTIONS AND COMPLETE ANSWERS
Block X of mass M slides across a horizontal surface where friction is negligible. Block X collides with
block Y of mass 2M that is initially at rest, as shown in Figure 1. After the collision, both blocks slide
together with a speed vs , as shown in Figure 2. 9/2Mv^2
What is the speed of the center of mass of the two-block system immediately before the collision?
The speed is v.
How could a student verify that the collision under consideration is an inelastic collision for the two-
block system? By comparing the final kinetic energy of the system with the initial kinetic energy of
the system
Block X of mass M travels with a speed v0. Block Y of mass 2M travels with a speed 2v0. Both blocks
travel toward each other and collide. After the blocks collide, they separate so that the kinetic energy of
the system remains conserved. Which of the following equations for the conservation of momentum
could a student use to help determine the speed vf of each block after the collision?
m0v0−4m0v0=m0vXf+2m0vYf, because the two blocks initially travel in opposite directions, and
the blocks do not stick after the collision.
Block X and block Y travel toward each other along a horizontal surface with block X traveling in the
positive direction. Block X has a mass of 4kg and a speed of 2ms. Block Y has a mass of 1kg and a speed
of 1 ms. A completely inelastic collision occurs in which momentum is conserved. What is the
approximate speed of block X after the collision? 1.4 m/s
, Block X and block Y travel toward each other along a horizontal surface with block X traveling in the
positive direction. Block X has a mass of 2kg and a speed of 3m/s. Block Y has a mass of 1kg and a speed
of 3m/s. After the collision, block X travels in the horizontal direction with a speed of 1m/s in the
negative direction. What is the speed of block Y if the collision is elastic? 5 m/s
Cart X travels in the positive direction along a horizontal surface, and cart Y travels in the positive
direction. The carts collide, and a student collects data about the carts' velocities as a function of time
before, during, and after a collision, as shown. The masses of both objects are known. Which of the
following best indicates how the student should use the graph to determine whether the collision is
elastic or inelastic and provides a correct justification? Using the known mass and known velocity
for each cart to determine the kinetic energy of the system before and after the collision, because the
kinetic energy changes in an inelastic collision
In an experiment, two objects, Object X and Object Y, travel toward each other and collide. Data are
collected about each object before, during, and after the collision to create a graph that shows the
momenta of Object Xand Object Y as a function of time. How should a student use the data found on the
graph to verify the conservation of momentum? The vector sum of the momenta should be
compared, because momentum is a vector quantity.
A student must conduct an experiment to verify the conservation of momentum. Cart X and Cart Y travel
toward each other and eventually collide, as shown in the figure. The student has access to the two
carts, one mass balance, and two motion detectors. If the mass of each cart is known, how should the
student arrange one or both motion detectors so that the student can collect enough information about
the motion of the carts, in order to verify the conservation of momentum of the system? 2 motion
detectors outside the collision
A student conducts three experiments in which two carts, cart 1 and cart 2, travel toward each other and
collide. A graph of each cart's momentum as a function of time is shown above. In which experiment, if
