1. An
introduction
to levers
Featuring
Wile e Coyote

2. pivot
Moment
Force

3. Where is the
pivot?

4. 5N Force 3. Which direction will the .What does see-saw turn?
this number
Mean?
2. What is
this?
A pivot
Anti-clockwise
Force

5. How can we increase the size of the moment (the turning effect)?
Pivot
Distance from force to pivot
Force (effort)

6. How are force, distance
and moment related?
moment F x d

7. 10cm 5N 50Ncm pivot Calculate the moment (turning effect) of the force
applied to the see-saw. Give the units.

8. 5cm 5N 25Ncm pivot Calculate the moment (turning effect) of the force
applied to the see-saw. Give the units.

9. 10cm
100Ncm
10N
pivot
Calculate the moment (turning effect) of the force
applied to the see-saw. Give the units.

10. 2m
Moment
= 500Nm
pivot
250N
Force

11. That's all folks

12. To use calculations to explain why objects can be balanced.
2. To calculate how to balance moments
Objectives: Level 7

13. 10m 10m 10N 10N pivot The moments of the forces are balanced.
Left
Moment
Right
Moment
100Nm
100Nm
10N
10N
pivot
The moments of the forces are balanced.
The see-saw is BALANCED. But why?

14. 10m 7m 10N 10N pivot The moment of force on the left is bigger
Right
Moment
100Nm
70Nm
10N
10N
pivot
But what happens if the blue dragon moves
in a little?
The moment of force on the left is bigger

15. 10m 10m 20N 10N pivot The see-saw is BALANCED. But why?
Left
Moment
Right
Moment
100Nm
200Nm
20N
10N
pivot
The moment of the force is greater on the right
The see-saw is BALANCED. But why?

16. But can we balance them both again? How?
Left
Moment
Right
Moment
100Nm
100Nm
20N
10N
pivot
But can we balance them both again? How?

17. 4m
10m
200N
500N

18. 4m
2.5m
640N
400N

19. Where should the loading platform be on the loading arm to carry each load safely?

21. Moments and Levers Answer these :- 1. What is the moment of
this force ?
2. What is the moment of
this force?
3. What is the length of this
lever if the moment is
8 Nm ?

22. For each of these, write “balanced” or “unbalanced”.
Balanced both 10Nm
Balanced both 120Nm
Unbalanced: Left is 160Nm, right is 165Nm
Unbalanced: left is 16Nm, right is 15Nm

23. 8m 14Kg 3Kg 60m All of these see-saws are balanced.
Work out the missing number for each one. 8m
14Kg
3Kg
60m