ROTATIONAL MOTION

How does the length of the moment arm affect torque?

• No effect
• Reduces force
• Greater moment arm produces greater torque for the same force
• Makes torque zero

In rotational equilibrium, what is the net torque about any point?

• Equal to force
• Maximum
• Zero
• Infinite

Why can't the centre of gravity be determined by balancing a body on a point alone?

• It always works perfectly
• Gravity disappears
• The body must be spherical
• Balancing finds only one possible position, not the exact CG without multiple trials

What is the main purpose of assuming the rod is homogeneous in Example 6.8?

• To reduce cost
• To make it shiny
• To ensure the centre of gravity is at the geometric centre
• To decrease length

How does the position of the knife edges affect the stability of the rod?

• No effect
• Closer edges increase stability
• Closer edges reduce stability by decreasing support base
• They make the rod heavier