The foot-pound force (symbol: ft·lbf), is a U.S. customary unit of work, or energy. It is frequently abbreviated incorrectly to foot-pounds. It is also called a dynam.
1 foot-pound force is:
- 1.355 817 948 331 400 4 J (exactly)
- 1.355 817 948 331 400 4 N.m (exactly)
- 0.001285 British Thermal Units
- 0.323832 Calories
Unit of work or energy
To calculate a foot-pound force, you can use this formula,
- W = F · d or transitional kinetic energy = F · d
is work (in foot-pound force
is force (in force">pound force
), and d
is distance (in feet) over which the force is applied (measured in the direction of the force).
Origins of foot-pound force
Foot-pound force is derived from the original equation of KE = wz.Where as KE is kinetic energy, w is the weight of the body and z is the average velocity of the falling body times the time of that fall.
These are the factors for w. w = m*g/gc Where as w is weight, m is mass, g is the local acceleration of gravity and gc is the dimensional constant.
These are the factors for z. z=1/2*v*tWhere as z is the average velocity of the falling body times the time of the fall, ½ is the coefficient to find the average velocity, v is the velocity and t is the time of fall.
When wz is fully factored to its four UOM (Units of measure)than reduced, the two remaining factors left are F and d. With these two variables left, this proves mathematically that energy of motion is force through distance, as in the original experiment of the two falling objects; force though distance
The four UOM are F [Force (pound force)], d [distance (foot)], m [mass (pound mass)], t [time (second).]
Unit of torque
The foot-pound force is also the unit of torque, which is conventionally expressed in SI units as newton-meters rather than joules. Sometimes the order of the units is reversed for torque, expressed as poundral rather than foot-pound force.