In the torque equation T = F x D, what does T represent?

• A. Torque
• B. Time
• C. Temperature
• D. Tension

Answer: (A)

Torque is the turning effect a force has about an axis. In the expression T = F × D, T is the torque created by applying a force F at a distance D from the rotation axis. The distance D, or lever arm, is the shortest distance from the axis to the line of action of F. If F is perpendicular to D, the torque magnitude is simply F times D; in general it is F × D × sin(theta) with theta the angle between F and the lever arm. The direction of the torque follows the right-hand rule and points along the axis of rotation. The units are Newton-meters. Time, temperature, and tension describe other quantities and don’t represent the rotational moment about an axis.