Physics practice Test Chapters C3-C5 Name _________________________

The numbers in parenthesis give the relative value of each question.

Circle the correct answer (3points/question)

A system consists of 2 billiard balls on a pool table. If the balls collide is the contact interaction internal or external?

A It depends.

B Internal

C External

A system consists of 2 billiard balls on a pool table. If the balls collide is the contact interaction between the balls and the table internal or external?

A It depends.

B Internal

C External

This room is an inertial reference system.

A True

B False

An accelerating car is an inertial reference system.

A True

B False

An elevator whose cable has been cut is an inertial reference system.

A True

B False

The Earth is an inertial reference system.

A True

B False

Because momentum is conserved, when you stand on the floor of this room and jump into the air, the Earth must rebound.

A True

B False

Two identical balls floating in space collide. The white ball was initially moving to the right along the dotted line until it hit the black ball which was initially at rest. This outcome is a possibility.

A True

B False

(5) Explain the reason for your answer

Two identical balls floating in space collide. The white ball was initially moving to the right along the dotted line until it hit the black ball which was initially at rest. This outcome is a possibility.

A True

B False

(5) Explain the reason for your answer

Two identical balls floating in space collide. The white ball was initially moving to the right along the dotted line until it hit the black ball which was initially at rest. This outcome is a possibility.

A True

B False

(5) Explain the reason for your answer

Two identical balls floating in space collide. The white ball was initially moving to the right along the dotted line until it hit the black ball which was initially at rest. This outcome is a possibility.

A True

B False

(5) Explain the reason for your answer

Before they collide the momentum of two objects is shown by these two vectors: If the two objects stick together after the collision, what must their final momentum be?

A

B

C

D

(5) Explain the reason for your answer

Before they collide the momentum of two objects was: If one object had a momentum of after the collision, what must the momentum of the second object be?

A

B

C

D

(5) Explain the reason for your answer

(15) Explain what is meant by “the conservation of momentum” and tell under what circumstances it applies.

(15) Explain completely what is meant by “inertial reference system”.

(15) Two cars collide. How do you know whether or not the law of conservation of momentum applies to this situation? Explain completely.

A 1000 kg car is traveling north at 20 m/s when it is struck by a second car (750 kg) that was traveling east. The two stick together after the collision. They are observed to be traveling at an angle of 60º north of east after the collision. How fast was the 750 kg car traveling before the collision?

(5) State the principle to be used in solving this problem.

(15) Explain in detail how this principle is used to solve the problem.

(5) 5. Draw a clear figure and that shows the data.

(10) Set up the equations and solve the problem.

A 70 kg man is standing at one end of a 2000 kg railroad car that is on a completely frictionless surface. The man and walks 8 m, to a point where he is 2 m from the other end of the 10 m car. How far does the car roll on the frictionless track during this time?

(10) What does the principle of the conservation of momentum tell us about this problem?

(10) Clearly explain how the principle is applied to solve the problem.

(5) Draw a clear figure and show the data.

(10) Write the equations and solve them to find the answer.