Levers and simple machines – basic principles
How it works
A lever is a simple machine: a rigid bar or a solid body can move around a pivot point. The lever arm is the distance between the pivot point and the point where a force acts. Levers make lifting or moving loads easier because a smaller force is needed with a longer force arm. The law of the lever states: force × force arm = load × load arm. There are one-sided and two-sided levers. Other simple machines are the inclined plane, the fixed and movable pulley, as well as the wheel and axle.
The law of the lever states: The forces acting on a lever are in inverse proportion to their lever arms. In equilibrium, the product of force and force arm on one side of the lever is equal to the product of force and force arm on the other side.
An example
A one-sided lever has a force arm of 40 cm and a load arm of 10 cm. How large must the force be to keep a load of 80 N in equilibrium?
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: Physics. The topic assignment may vary by federal state.