ROTATIONAL MOTION

What happens to the angular momentum if torque is applied parallel to it?

• Its direction changes but not magnitude
• It becomes zero
• It reverses direction
• Its magnitude changes but not direction

How is the direction of torque determined in vector form?

• By left-hand rule
• By direction of r only
• By direction of F only
• By the right-hand rule for cross product

What is the primary cause of precession in rotating bodies?

• Frictional forces
• Air resistance
• Internal vibrations
• External torque acting perpendicular to angular momentum

What is the consequence of leaving both strings in the bicycle rim experiment?

• The rim starts precessing
• The rim falls down
• The rotation stops
• The rim remains stable without precession

Why is the plane of the rotating rim vertical in the experiment?

• Because gravity pulls it vertically
• Because of air pressure
• Because of magnetic forces
• Because the axle is held horizontally with strings