1. Turning Forces and Centre of Gravity
Chapter 43

2. A Lever
A lever is a rigid body which is free to turn about a fixed point called the fulcrum.
Example:
Crow bar
Wrench

3. The Moment
The moment of a force tells us how much spin or circular motion a force can cause. x
Moment of a Force
Force
Perpendicular distance from the force to the fulcrum

4. Law of the Lever
The law of the Lever states that when a lever is balanced the sum of the clockwise moments equals the sum of the anticlockwise moments.

5. The Law of the Lever

6. Centre of Gravity
The centre of gravity is the point of an object where all the forces appear to act.

7. Equilibrium Equilibrium is when an object is balanced and not moving.
3 states of equilibrium:
Stable equilibrium
Unstable equilibrium
Neutral equilibrium

8. Stable Equilibrium
If given a slight push the object will return to the same position.

9. Unstable Equilibrium
If given a slight push the object will not return to the same position.

10. Neutral Equilibrium
If given a slight push the object will return to a similar position.

11. Stability
An object will topple over if its centre of gravity passes outside its base.

12. Stability Objects are more stable if they have: Examples A wide base
Low centre of gravity
Examples
Bunsen
Bus
Flower vase