Momentum, Work, Energy and Power

Linear Momentum

The product of the mass and velocity of an object

Newton’s second law in terms of momentum

The net force acting on an object is equal to the rate of change of momentum

Law of conservation of linear momentum

The total linear momentum of an isolated system remains constant/ conserved

Elastic collision

A collision in which both momentum and kinetic energy are conserved

Inelastic collision

A collision in which only momentum is conserved

Impulse

The product of the net force and the contact time

Work

The product of displacement and the component of the force parallel to the displacement

Gravitational potential energy

The energy an object possesses due to its position relative to a reference point

Kinetic energy

The energy an object has as a result of the object’s motion

Mechanical energy

The sum of gravitational potential and kinetic energy at a point

Law of conservation of energy

The total energy in a system cannot be created nor destroyed, only transformed from one form to another

Principle of conservation of mechanical energy

In the absence of air resistance or any external forces the mechanical energy of an object is constant

Work energy theorem

The work done by a net force on an object is equal to the change in the kinetic energy of the object

Power

The rate at which work is done or the rate at which energy is transferred

Efficiency

The ratio of output power to input power