1. Starter: What are the key differences between these two cars?
Centre of mass
Lesson 9/21
Where is the centre of mass of different objects?
Starter: What are the key differences between these two cars?

2. Glossary
Centre of mass: the point where an objects mass is thought to be concentrated.
Equilibrium: the state of an object at rest.

3. Where is the centre of mass of the following objects?

6. Where is the centre of mass ?

8. Task: balance some shapes.
1) Suspend a card shape from the metal bar.
2) Use the plum line to draw vertical line.
3) Suspend the card from a different place and draw a second line.
The centre of mass is where the 2 lines meet.

9. Results + conclusion What did you notice about symmetrical shapes?
What about asymmetrical shapes?

10. This basket is in equilibrium
This basket is in equilibrium. Its weight does not exert a turning force. W

11. What will happen here? W
The basket returns to equilibrium because its weight acts as a turning force. It is said to be freely suspended.

12. Complete a past paper question.
Only part “a” for now please