turning effects of forces and centre of gravity

Which one describe the point through which the whole weight of the body acts?

• Inertial Point

• Center of gravity

• Centriod

• Central point

Where the center of gravity of a circle lies?

• At its centre

• Anywhere on its radius

• Anywhere on its circumference

• Anywhere on its diameter

Which simple method can be used to find the centre of gravity of an object?

• stop watch

• plumbline

• pendulum

• gauge

What is one way you might increase the stability of an object?

• Lower the center of gravity

• Raise the center of gravity

• Increase the height of the object

• Shorten the base of the object

what is one method other than a plumb bob that can be used to find the centre of gravity?

• Dropping the object and seeing how it falls

• Finding the point that the object balances

• Measuring the object with a ruler

• Looking at the lightest part of the object

Do all objects have a centre of gravity?

• No objects have a centre of gravity

• Only some objects have a centre of gravity

• Only very heavy objects have a centre of gravity

• Yes all objects have a centre of gravity

Why is the car on the left unstable?

• Its centre of mass is high

• it has a narrow base

• it has a high height

• all of the above

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 see-saw is made by resting a long plank of wood with its centre of gravity on the barrel.

A boy sits on one side of the barrel and a girl sits on the other side so that the see-saw is balanced.

Which of the following statements must be true?

• boy’s weight = girl’s weight

• distance x = distance y

• moments of the girl = moments of the boy

• moment of the girl > moment of the boy

The diagram shows a balance being used to find the weight of a baby.

At equilibrium, the pivot is nearer to the 40 N balancing weight than to the baby.

What is the weight of the baby?

• less than 40 N

• 40 N

• more than 40 N

• impossible to tell without a scale on the beam