The Physics of Energy
 Energy and Work Work is defined as the scalar product of the force applied and the distance moved by the object. If we consider work done by a non-consistent force moving an object from point s1 to s2, the equation for it would be, Work and energy share the same unit and it's measured in the SI(International Standard) unit of joule(J) which is the product of Newton(unit for force) and meter. foot-pound is also commonly used in the US. And the relationship between the two units is, Consider an object of mass m pulled with a force F with an inclination over a horizontal plane. If we ignore the force of friction, the forces acting on the body would be the gravitational force: mg, the normal force, and the force applied. Since the normal force(straight upwards) and the gravitational force(straight downwards) are perpendicular to the direction of the object, the work done by the forces is equal to zero. In the same manner, the vertical component of the force applied does not do any work on the object since it's perpendicular to the direction of its motion. The only force that does work is the horizontal force of the object's kinetic energy.