Turning Effect and Equilibrium

The moment of a force causes an object to

• move forward

• move backward

• stop moving

• turn about a fixed point

The turning effect of a force on a door is greater when it is applied at

• A point near the hinges and perpendicular to the door

• A point near the hinges and parallel to the door

• A point far away from the hinges and perpendicular to the door

• A point far away from the hinges and parallel to the door

Two equal and oppositely directed forces acting on an object will be in equilibrium

• Only if they act on the same point on the object

• If they are separated by a distance

• When they are balanced by a third force

• when their moments about the same point are equal

The diagram shows a light beam pivoted at one end. What is the effort required to lift the load?

• 50

• 67

• 100

• 200

Jack has a weight of 300 N and sits 2.0 m from the pivot of see-saw. Jill has a weight of 450 N and sits 1.5 m from pivot. Who will move down?

• Jack

• Jill

• Both of them

• None of them

Tags

NGSS.MS-PS2-4

A nut can be loosen more easily with

• A short spanner because a large turning effect can be produced

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

• A heavy spanner because a larger force can be produced.

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

The diagram shows a gauge which measures the amount of liquid in a tank. At which position should the pivot be placed so that the pointer moves the greatest distance as the tank is emptied?

• A

• B

• C

• D

What is the force F needed to balance the bar shown?

• 3

• 4

• 6

• 8

A light metre rule is allowed to pivot freely at the zero end. The other end is supported by a spring balance. A weight of 200N is then hung at the 40cm mark. The metre rule stays horizontal. What is the reading on the spring balance?

• 80

• 40

• 8

• 4

Which one of the following activities does not apply the turning effect of a force?

• swinging on a swing

• sliding down a slide

• moving up and down on the see-saw

• rowing a boat