Levers


lever_1.jpeg
Required 2N of effort to move.

The fulcrum is the place where the lever moves.
The load is the weight.
The effort is how much work it takes to move the lever.



Where you place the effort, the load and the fulcrum all influence how hard it is to move the lever.

Try it!

Only move one part of the device at a time to see how it affects the work it takes to move the lever.

Lever_2.jpeg
Required >10N of effort to move.


Move the EFFORT back and forth, closer to the fulcrum and further away from it.
What happens to your effort in each position?




Conclusion:

When the load is
FURTHER
from the fulcrum,
it is easiest to move the load if the
effort is
further
from the fulcrum.





Try it again, only differently.
Lever_3.jpeg
.5 N of effort required.


Now move the LOAD back and forth, closer to the fulcrum and further away from it.
What happens to your effort in each position?



Conclusion

It is easier to move the load when the load is closer to the fulcrum IF the effort is further from the fulcrum.

lever_1.jpeg
2.5 N of effort required


















There are THREE classes of levers.

Use this to help you remember the classes, FLE 123 (F = fulcrum, L = load, E = effort)

When the _ is the in middle:
F
L
E
This is the class lever:
1
2
3
What are some example levers for each class?


First Class (_ is in the middle):

Lever1.gif
120px-Palanca-tipo1.jpg
  1. Can opener and bottle opener
  2. Crowbar
  3. Hammer, when pulling a nail with the hammer's claw
  4. Oars
  5. Pliers (double lever)120px-Fysik_vridmoment.png
  6. Scissors (double lever)
  7. Seesaw (also known as a teeter-totter)


Second Class (_ is in the middle):
Lever2.gif

600px-Yksivartinen_vipu.svg.png
  1. Crowbar 79px-Crowbar_(PSF).jpg
  2. Door
  3. Nutcracker
  4. Springboard (diving board)
  5. Wheelbarrow
  6. Wrench


Third Class (_ is in the middle)
Lever3.gif
  1. Arm
  2. Baseball bat
  3. Boat paddle
  4. Broom
  5. Door
  6. Fishing rod
  7. Hockey stick
  8. Tongs
  9. Tweezers
  10. Mousetrap
  11. Nail clippers, the main body handle exerts the incoming force
  12. Shovel (the action of picking or lifting up sand or dirt)
  13. Tools, such as a hoe
  14. Stapler