How it works

What is a Lever?

A lever is a device that we use to make it easier to lift, cut, grab, maneuver and many other tasks. You can find levers in scissors, tools, kitchen and cleaning utensils, office supplies, sports equipment, bicycles, switches, handles, and your own body. They are everywhere! Every lever has three main components:
- Effort: : The input to the lever, the part you operate, or which is activated by another device, such as the brake cable on a bicycle, or the biceps muscle that lifts your forearm.
- Load: The output of the lever, the part that lifts, cuts, grabs or maneuvers.
- Fulcrum: A pivot, pin or stationary point that allows the effort and load to rotate.
Levers in a Flip Toy

The photo shows how a flip toy uses two levers to transmit force and motion from one place to another. Each of the craft sticks is a lever. Like a pair of scissors, the two levers share a common fulcrum. The part you squeeze, at the bottom of the craft sticks, is the input to the levers or the effort. The load is where the sticks do their job: pulling on the string. The fulcrum is the bottle cap, which allows both sticks to rotate, so the bottom moves together and the top moves apart.
The Law of the Lever
- If the fulcrum moves up, the string will open with more force, but not as wide
- If the fulcrum moves down, the string will open wider, but with less force.

Stem at home