# Torque

Written by Jerry Ratzlaff on . Posted in Properties

Torque, also called "moment of force", is a rotational moment; it is a measure of how much twisting is applied to a fastener. The units used to measure torque are in the form of force times length. Usually measured in newton-metres (Nm) if metric units are used or pounds feet (lb-ft) when imperial units are used.

## formula

$$T = l F$$

$$T = I a_a$$

Where:

$$T$$ = torque

$$l$$ = length, moment arm

$$F$$ = force

$$I$$ = moment of inertia

$$a_a$$ = angular acceleration

Solve for:

$$F = \frac {T}{l}$$

$$l = \frac {T}{F}$$