MOMENTS

Moment is a quantity that tells turning effect of a force about turning point. 

• TRUE
• FALSE

What is the moment produced by the 15 N?

• 15 Nm (clockwise)
• 150 Nm (anti - clockwise)
• 1.5 Nm (anti - clockwise)
• 0.15 Nm (clockwise)

What is the net Moment?

• 0 Nm
• 4 Nm (clockwise)
• 30 Nm (clockwise)
• 30 Nm (anti-clockwise)

State the principle of moments.

• When a system is in equilibrium, the sum of the total clockwise moment is equal to the sum of the total anti-clockwise moment about the same pivot.

• When a system is in equilibrium, the sum of the total clockwise moment is greater the sum of the total anti-clockwise moment about the same pivot.

• When a system is in equilibrium, the sum of the total clockwise moment is less than the sum of the total anti-clockwise moment about the same pivot.

• When a system is in equilibrium, the sum of the total clockwise moment is equal to the sum of the total anti-clockwise moment about the different pivot.

What is the moment of the 10 N force about point A (M_A)?

• 10 N·m
• 30 N·m
• 13 N·m
• (10/3) N·m 

What is the moment acting on the seesaw?

• 1.6Nm
• 15Nm
• 16N
• 4Nm

A nut can be loosened more easily with

• a short spanner because a larger turning effect can be produced.

• a long spanner because a larger turning effect can be produced.

• a long spanner because a larger force can be produced.

• a short spanner because a larger force can be produced.

A force is a applied to a long crowbar so as to move a large rock.

Which labelled arrow represents the smallest force needed to move the rock?

• A

• B

• C

• D

Which diagram best demonstrates the use of the moment of a force?

• A

• B

• C

• D

The figure below shows a man lifting a heavy rock using a steel bar. He pushes downwards on the end of the bar with a force F.

Which pivot positions allows the force F to be as small as possible?

• A

• B

• C

• D