Moment And Centre Of Gravity

Question 1

Moment of force = ?

Answer 1

(Force) x (perpendicular distance from the force to the fulcrum)

Question 2

Define a lever?

Answer 2

Any rigid body that is free to turn about a fixed point or axis called a fulcrum.

Question 3

What is the law of the lever?

Answer 3

When a lever is balanced by any number of forces, the sum of the clockwise moments acting on it is equal to the sum of the anti-clockwise moments.

Question 4

What is the centre of gravity of an object?

Answer 4

Is the point through which the weight of the object appears to act

Question 5

Describe an experiment to investigate the law of the lever

Answer 5

• tie a string around the centre of the metre stick. Hang the metre stick from the retort stand. Make sure the metre stick is balanced.
• hang 1N weight on the left side of the metre stick and hang 2N weight on the right side of the metre stick, move the weights until the lever is balanced.
• calculate the moment of each of these weights.
• repeat this experiment with the same weights in different positions.

Question 6

What do you call an object that is balanced?

Answer 6

In equilibrium.