ROTATIONAL MOTION

What is the net force on a rod when two equal and opposite forces act perpendicularly at its ends?

• 2F
• F
• Zero
• F/2

What is the net torque on a rod when two equal forces act perpendicularly at its ends in the same direction?

• 2aF
• aF
• Zero
• F/a

What is the moment of force at point A on a rod AB of length 2a, where a force F acts perpendicularly at A, about the midpoint C?

• 2aF
• aF/2
• 0
• aF

Why does a compass needle experience a couple in Earth's magnetic field?

• Because the forces are unequal
• Because the needle is heavy
• Because only one pole experiences force
• Because equal and opposite forces act on its poles with different lines of action

In the case of a rod with equal and opposite forces applied perpendicularly at its ends, what type of motion does it undergo?

• No motion
• Linear acceleration
• Oscillation
• Pure rotation