Torque
In physics, torque is the tendency of a force to turn or twist. If a force is used to begin to spin an object, or to stop an object from spinning, a torque is made.
The force applied to a lever, multiplied by the distance from the lever's fulcrum, multiplied again by the sine of the angle created, is described as torque. This is also known as "r cross f," or "force times fulcrum distance times sine theta."
Fulcrum
Fulcrum is the axis of rotation or point of support on which a lever turns in raising or moving something.
Equation
The equation for torque is:
- [math]\displaystyle{ \boldsymbol \tau = \mathbf{r}\times \mathbf{F}\,\! }[/math]
where F is the force vector and r is the vector from the axis of rotation to the point where the force is acting.
The units of torque are force multiplied by distance.[1] The SI unit of torque is the newton-metre. The most common English unit is the foot-pound.
References
Other websites
- "Horsepower and Torque" An article showing how power, torque, and gearing affect a vehicle's performance.
- a discussion of torque and angular momentum in an online textbook
- Torque and Angular Momentum in Circular Motion on Project PHYSNET.
- An interactive simulation of torque