ROTATIONAL MOTION

What happens to the centre of mass when a system undergoes phase change?

• It stops
• It accelerates
• Its motion depends only on external forces, not on phase
• It evaporates

How is the centre of mass used in astronomy?

• To measure brightness
• To change orbits
• To locate the balance point of celestial systems
• To create black holes

What is the effect of a constant external force on the centre of mass velocity?

• It remains constant
• It decreases exponentially
• It changes linearly with time
• It becomes zero

How does the centre of mass help in accident reconstruction?

• To paint the vehicles
• To reduce insurance
• To determine vehicle motion from impact dynamics
• To improve music systems

What is the role of the centre of mass in planetary motion?

• It stops the motion
• It increases gravity
• It defines the common point about which bodies orbit in a system
• It creates light