ROTATIONAL MOTION

What is the torque about the center of a rod when two equal and same-direction forces act perpendicularly at the ends?

• 2aF
• aF
• Zero
• F/a

Why is the concept of a couple important in engineering?

• Because it increases weight
• Because it reduces speed
• Because it allows rotation without disturbing the position of the center of mass
• Because it makes materials stronger

What is the motion of a body when net torque is zero but net force is not zero?

• Rotation
• Pure translation
• Vibration
• No motion

What is the motion of a body when net force is zero but net torque is not zero?

• No motion
• Linear motion
• Oscillation
• Pure rotation

How does the point of application of force affect rotational motion?

• It changes the mass
• It affects only speed
• It determines the torque and thus the rotational effect
• It has no effect