Work

—When a force acts upon a body so as to overcome resistance and produce motion, work is performed, and the measure of the work is the product of the force by the distance moved. Work is done when a body is lifted against the force of gravity, when a body is caused to overcome the resistance of friction, ete. The common units of work are the foot pound and the erg. A foot pound is the work done when a force of one pound acts through a distance of one foot; an erg is the work done by a force of one dyne acting through a distance of one centimeter.