Moments

State the principle of moments

• A 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.

• B 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.

• C 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.

• D 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 acting on the seesaw?

• 1.6Nm

• 15Nm

• 16N

• 4Nm

What is the size of the moment shown by the black arrow?

• 30 Nm

• 36 Nm

• 40 Nm

• 60 Nm

A beam lies on a pivot. If d2 > d1 and F1 = F2, which direction will the beam turn?

• turn clockwise

• turn anti-clockwise

• not turn

True or False: The magnitude of the moment decreases as the force acts further from the pivot point.   $M=d\times F\perp$  

• TRUE

• FALSE

What is the unit of moment of force?

• N

• m

• Nm

• N/m

A seesaw is unbalanced with two people of different masses sitting equal distances from the center. Which of the following will result in equilibrium?

• The larger person moving further away from the center.
• Moving the smaller person closer to the center.
• Moving the smaller person further from the center.
• Making the larger person do nothing.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A wrench is used to tighten a nut. A 7 N perpendicular force is applied 2 m away from the axis of rotation. What is the torque applied to the wrench?

• 14 Nm

• 3.5 Nm

• 7 Nm

• 15 Nm

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 boy of weight 600N sits on the see-saw as shown at a distance of 1.5m from the pivot. What is the force F required at the other end to balance the see-saw?

• 450 N

• 350 N

• 4.5 N

• 200 N