World 1 · Levers · 5 minWhat Is a Lever?
A stiff bar that pivots on a point
Teaching this? Open projector mode
A lever is the simplest machine: a rigid bar that turns around a fixed point called the fulcrum. In the first-class arrangement shown here, push down on one end (the effort) and the other end lifts the load.
The magic is mechanical advantage — the longer your effort arm compared to the load arm, the less force you need. A long bar lets one person lift a boulder.
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