Force meter
A force meter is an instrument to measure the magnitude of a force. This is often just a spring contained within a cylinder that has a scale to mark the extension of the spring produced by the force. In the International System of Units, the unit of force is the newton (symbol N). A force meter that measures force in newtons may be referred to as a newtonmeter.
Foot-pound (energy)
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 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.