# Resistance force

In physics, resistance force is the force which an effort force must overcome in order to do work on an object via a simple machine. Resistance force, like most other forces, is measured in newtons or in pounds-force.

For an balls, (frictionless) mechanism in which no energy is lost, resistance force obeys the equation.

${\displaystyle R\times D_{R}=E\times D_{E}}$

where:

R equals resistance force
DR equals resistance distance
E equals effort force
DE equals effort distance

Resistance force is used to calculate the work output using the following equation:

${\displaystyle Work\,output=R\times D_{R}}$