Principle of Moments

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 anticlockwise moment acting on this crane?

• 80,000Nm

• 100,000Nm

• 120,000Nm

• 140,000Nm

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 resultant moment acting on the seesaw?

• 1.6 Nm (anticlockwise direction)

• 1.6 Nm (clockwise direction)

• 4 Nm (anticlockwise direction)

• 4 Nm (clockwise direction)

Assuming the system is in equilibrium, calculate the missing distance d

• 3.4 m

• 2.8 m

• 4.4 m

• 1.6 m

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

At what distance should a 2N load placed from the pivot so that the see saw won't move?

• 0.2m

• 0.5m

• 0.45m

• 0.42m

Tags

NGSS.HS-PS2-1

Calculate the unknown force X!

• 4.0 N

• 6.0 N

• 10 N

• 12 N