Moments And Centre Of Gravity

Question 1

Fulcrum

Answer 1

The fixed point or line through which something swings

Question 2

Turning effect of a force

Answer 2

Can be changed by:
Increasing the size of the force
Increasing the distance from applied force to the fulcrum

Question 3

Moment

Answer 3

The measure of the turning effect of the force is called the moment (torque)
Moment = (force) x (perpendicular distance from the fulcrum to the force)

Question 4

Levers

Answer 4

Turn around a fixed point called the fulcrum. Levers allow us to move of turn things more easily.
A lever is any rigid body that is free to turn around a fixed point or axis called the fulcrum.

Question 5

Law of the lever

Answer 5

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 6

Centre of gravity

Answer 6

The centre of gravity of an object is the point through which the weight of the object appears to act

Question 7

Equilibrium

Answer 7

Fulcrum above centre of gravity = stable equilibrium
Fulcrum below centre of gravity = unstable equilibrium
Fulcrum at centre of gravity = neutral equilibrium

Question 8

Low centre of gravity

Answer 8

Helps stability when vertical line from centre of gravity is inside its base

Question 9

Wide base helps stability

Answer 9

Race cars have wide bases and wheels far apart so that the centre of gravity will stay directly above the base