ROTATIONAL MOTION

How does gravity contribute to torque on individual particles?

• By pushing sideways
• By creating heat
• By acting upward
• By acting downward and creating a turning effect about CG

What is the condition for zero net torque in a balanced body?

• All forces must be zero
• Only one force should act
• Sum of clockwise and counterclockwise torques must be equal
• The object must be circular

Is the centre of gravity the same as the centre of buoyancy?

• Yes, they are the same
• No, but they always coincide
• No, centre of buoyancy is for fluid upthrust, CG is for gravity
• Yes, both are central points

What happens to the reaction force if the cardboard is heavier?

• It decreases
• It becomes zero
• It changes direction
• It increases to match the weight

Why is the position vector measured from the CG in torque calculations?

• To complicate the equation
• To reduce mass
• Because torque is calculated about a reference point
• Because it increases gravity