ROTATIONAL MOTION

What determines whether a rigid body will rotate when forces are applied?

• Only the number of forces
• The color of the body
• The net torque produced by the forces
• The temperature

Why is the angular momentum of a particle not zero even when it moves in a straight line past a point?

• It is always zero
• Because the mass is large
• Because the velocity vector has a perpendicular component relative to the position vector
• Because time is infinite

What is the effect of a single external force applied at the center of mass of a free rigid body?

• It causes pure rotation
• It has no effect
• It causes translational acceleration without rotation
• It destroys the body

How does the conservation of angular momentum apply to planetary motion?

• It makes planets stop
• It changes their mass
• It explains why planets sweep equal areas in equal times
• It causes eclipses

What role do internal forces play in the equilibrium of a rigid body?

• They cause rotation
• They increase mass
• They do not affect the total force or torque on the body
• They change velocity