Levers are simple machines that use a pivot to balance loads and transfer effort. They work by using the principle that effort x distance = load x distance from the pivot point. Longer levers provide mechanical advantage by allowing smaller efforts to move larger loads over greater distances. Key terms related to levers include pivot, effort, load, turning effect, force, distance, weight, and lever.
Use navigation buttons rather than mouse click to navigate through the presentation.
Question pupils as to what is the common factor of these simple machines.
Have examples of scissors and other levers at hand to extend above examples
Question pupils as to what would happen if we placed a 5Kg weight at 1 or 2m? Then click on 1m or 2m button as appropriate!
Run through why this scenario balances.
Introduce term “turning effect”
Give examples on board of calculations using this formula.
Introduce terms Effort and Load.
Explain why this pair of scissors is a lever.
Have pupils choose which length of plank they could use to make the 5Kg weight lift the Sumo wrestler. When you have a consensus then click on the “Long” or “Short” plank button to see whether the pupil’s choose was right or wrong.
Have pupils explain why this is the correct choice!
Have pupils explain why this is an incorrect choice!
Run through key words again!
Presentation could be extended to cover the three types of levers in more depth (or better still with practical work) i.e., effort or distance magnifiers with emphasis of the position of the load and effort.