ROTATIONAL MOTION

What happens to the total angular momentum if the net external torque is zero?

• It increases
• It decreases
• It becomes zero
• It remains constant

Under what condition does the center of gravity coincide with the center of mass?

• They are always the same
• They differ by 1 meter
• When the gravitational field is uniform across the body
• The center of gravity is always higher

When is the total torque on a system independent of the choice of origin?

• When the system is at rest
• When the total external force is zero
• When the body is spherical
• When angular momentum is zero

Can a system experience zero net external force but still have non-zero net external torque?

• No
• Yes
• Only in space
• Only in vacuum

What additional condition is needed to prove that the rate of change of angular momentum equals total external torque?

• Forces must be gravitational
• Forces must be electromagnetic
• Forces between particles must act along the line joining them
• Forces must be zero