The unit of measure for the strength of something to do work. In the metric system it is known as the Newton.
The equation below is often used to describe the behaviour of forces on a body with mass. Where m is the mass (kg), a is the acceleration of the body and F is the forces acting on the body indexed by i for an arbitrary number of forces (n).
A sum of forces that is 0 will not accelerate the body, thus if moving it will continue to move at the same speed or if stationary it will remain stationary.
A convenient quantity that combines a set of quantities which when equated to another energy, to denote a conversion of energy form, can be used in many applications. It is measured in the metric system as Joules however it is not uncommon and often convenient to express energy in terms of Watt-hours.
// # % Include a statement or 2 about efficiency
Some useful equations:
Where: F is the force applied to an object; d is the distance it is pushed in the direction of that force; m is the mass of an object; v is the speed it is travelling at; i is the current running through as circuit; V is the voltage across the circuit; t is the duration that the current has been running for; g is the gravitational constant (9.81, ~10); and h is the change in height of an object raised.