ROTATIONAL MOTION

If a particle is moved from x=1 to x=3, how does its contribution to ∑mi xi change?

• It decreases by 2mi
• It increases by 2mi
• It remains same
• It doubles

How does the centre of mass of a system of particles in free space move?

• With constant acceleration
• With constant velocity if no external force
• It oscillates
• It remains fixed

What is the main advantage of using the centre of mass frame in physics problems?

• Gravity is eliminated
• Internal motions can be analyzed independently
• All velocities are zero
• Forces vanish

If a system has a centre of mass at the origin, what is the value of ∑mi xi?

• Total mass
• Zero
• Total momentum
• Infinity

How does the centre of mass of a system change if a heavy particle is moved slightly?

• It shifts slightly
• It shifts significantly
• No change
• It reverses