# Torque

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:

\(F = \frac {T}{l} \)

\(l = \frac {T}{F} \)