Moments of forces

Question 1

Define moment

Answer 1

• is the turning effect of a force about a point
• anticlockwise moments are usually thought of as positive moments whereas clockwise ones are negative

Question 2

Formula to calculate the moment of a force

Answer 2

• Moment = force x distance from point to the line of action of the force
• unit is Newton metre (Nm)

Question 3

Define rigid bodies

Answer 3

• is an object that has a size and shape that are important in a problem
• able to rotate as well as move along
• keeps its shape when the forces act on it

Question 4

Define a rigid body in equilibrium

Answer 4

when the total force is zero and the total moment is also zero

Question 5

Describe what uniform means

Answer 5

it means the centre of mass is at the centre of the object - its acts in the middle