ROTATIONAL MOTION

How does the concept of center of mass help in analyzing collisions?

• It eliminates the need to study collisions
• It makes collisions more complex
• It changes the outcome of collisions
• It allows prediction of overall motion independent of internal details

What is the relationship between the total external force and the acceleration of the center of mass?

• F_ext = M/v
• F_ext = P/t
• F_ext = Mv²/r
• F_ext = M*a_cm

Can the center of mass of an object lie outside the physical material of the object?

• No, never
• Only in liquids
• Only in gases
• Yes, as in a ring or hollow sphere

What happens to the center of mass of a system when a person walks from one end of a boat to the other on still water?

• It moves forward with the person
• It moves backward
• It sinks lower in water
• It remains in the same position

How does the principle of conservation of momentum apply to rocket propulsion?

• The rocket creates momentum from nothing
• External air pushes the rocket forward
• Gravity pulls the rocket forward
• The rocket gains forward momentum as exhaust gases carry equal backward momentum