ROTATIONAL MOTION

What is the condition for no rotation in a rigid body?

• Net force is zero
• Only F1 = 0
• Net torque about any point is zero
• N = W

What is the source of the restoring torque in the ladder system?

• Weight W
• Normal force N
• Friction F
• Force F1 from the wall

How does the length of the ladder affect the normal reaction N?

• N decreases with length
• N is unaffected
• N equals W, so it increases with ladder mass
• N becomes zero

What is the importance of the right angle at C in the ladder triangle?

• It makes the ladder stable
• It reduces weight
• It allows use of Pythagoras theorem to find BC
• It increases friction

What is the analogy between Newton's second law for linear and rotational motion?

• F = mv and τ = Iω
• F = p and τ = L
• F = ma and τ = Iα
• F = E and τ = K