Work energy and power

Principle of conservation of energy

Energy cannot be created nor destroyed. It can only be transferred from one form to another.

Energy

Energy is the capacity for doing work. It is a scalar vector.

Work done

Work done is a measure of the amount of energy transferred when energy moves from one form to another

Joules in SI base units

Kgm²s²

Internal energy

The sum of the random potential and kinetic energies of atoms in a system

Elastic potential energy

Energy stored in an object as a result of a reversible change in its shape

Gravitational potential energy

Energy of an object due to its position in a gravitational field

Kinetic energy

Energy due to the motion of an object with mass

Power

The rate at which work is done

Watt in SI base units

kgm²s³

Efficiency

The ratio of useful work to work done in a system

In a Sankey diagram what are the width of the arrows proportional to

To the amount of energy it represents

Efficiency equation

(Useful output / input) x 100