Usage
The foot-pound is often used to specify the muzzle energy of a bullet in small arms ballistics, particularly in the United States.
"Foot-pound" is sometimes also used as a unit of torque (see Pound-foot (torque)). In the United States this unit is often used to specify, for example, the tightness of a bolt or the output of an engine. Although they are dimensionally equivalent, energy (a scalar), and torque (a vector) are distinct physical quantities. Both energy and torque can be expressed as a product of a force vector with a displacement vector (hence pounds and feet); energy is the scalar product of the two, and torque is the vector product.
Read more about this topic: Foot-pound (energy)
Famous quotes containing the word usage:
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—A.J. (Alfred Jules)
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