Force, work, energy, power

Force is a vector quantity, a push or pull which changes the shape and/or motion of an object. In SI, the unit of force is the newton (N), and in Imperial, it is the pound (lb).

Weight is the gravitational force of attraction between a mass and the mass of the Earth. In SI, weight can be calculated as F = mg, where g = 9.81 m/s².

Newton's Second Law states that an unbalanced force F will cause an object of mass m to accelerate a, according to F = ma.

Momentum is a vector quantity, symbolized as p, and is calculated as p = mv. In SI, the unit is kg m/s.

Work is a scalar quantity, equal to the product of a force and the displacement of an object. It is calculated as W = Fs. In SI, the unit of work is the joule (J).

Energy is the ability to do work, with units the same as for work: joules (J), kilojoules (kJ), and foot-pounds (ft-lb).

Kinetic energy is the energy due to motion, calculated as Ek = 1/2 mv². In Imperial, it is expressed as Ek = w/2g v², where w is weight.

The kinetic energy of rotation is calculated as E = 1/2 Iω², where I is the moment of inertia and ω is the angular velocity in rad/s.