ROTATIONAL MOTION

Under what condition does a rigid body have only rotational motion?

• When no forces act on it
• When it is in free fall
• When it is moving in a straight line
• When it is fixed at a point or along a line

What is the relationship between angular displacement and angular velocity in rotational motion?

• Angular velocity is the integral of angular displacement
• They are unrelated
• Angular velocity decreases as displacement increases
• Angular velocity is the rate of change of angular displacement

How does a classical dancer performing a pirouette control their spin speed?

• By pushing the floor repeatedly
• By changing body mass
• By using air currents
• By adjusting their moment of inertia through body posture

What is the main assumption about internal forces in proving net internal torque is zero?

• Forces are perpendicular to the line joining particles
• Forces increase with distance
• Forces are negligible
• Forces between any two particles act along the line joining them

In which direction is the linear velocity vector of a rotating particle relative to ω and r?

• Parallel to ω
• Parallel to r
• At 45 degrees to both
• Perpendicular to both ω and r