12. which of the following can be calculated if the length of the effort arm and the length of the resistance arm are given? (points : 3)
the mechanical advantage of a lever can be calculated.
the mechanical advantage of a wheel and axle can be calculated.
the mechanical advantage of a pulley can be calculated.
the mechanical advantage of a wedge can be calculated.

The mechanical advantage of a lever can be calculated.

Explanation:

If the length of the effort arm and the length of the resistance arm are given we can calculated the mechanical advantage of a lever. It is also defined as the ratio of output force to the input force. Mathematically, it is given by :

Where

is the output force

is the input force

A lever is a simple machine in which there is a Plank that is free to free to rotate around a pivot. So, the correct option is (a) "the mechanical advantage of a lever can be calculated".

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