P1 - Conservation and dissipation of energy

Chemical Energy

The energy stored in chemical bonds eg. Food, fuel, batteries

Thermal Energy

The total energy of motion in the particles of a substance

Kinetic Energy

The energy of a moving object

Electrostatic/Magnetic Energy

The energy stored when repelling charges have been moved closer together or when attracting charges have been pulled further apart

Elastic Potential Energy

The energy of an object that is stretched or compressed

Gravitational Potential Energy

The energy stored in an object due to its height above the Earths surface

Nuclear Energy

The energy stored in the nucleus of an atom

Mechanical Work

A force moving an object through a distance

Electrical Work

Charges moving due to a potential difference

Heating

Due to temperature difference

Radiation

Energy that is transferred as a wave

Law of Conservation of Energy

States that energy cannot be created nor destroyed, it can only be transferred from one type to another

Wasted Energy

Energy that is not usefully transferred and transferred to the surroundings eg. Thermal, Sound

Closed System

No energy would be transferred out of the 'system' - NO NET CHANGE IN TOTAL ENERGY

Open System

Energy can be transferred out of and into the 'system' - A NET CHANGE IN TOTAL ENERGY

Work

Is done on an object when a force makes an object moves, whenever work is done energy is transferred

Work done (J) equation

Force (N) x distance (M)

Weight (N) equation

Mass (kg) x gravitational field strength (N/kg)

Gravitational potential energy (J) equation

Mass (kg) x Gravitational field strength (N/kg) x Change in height (m)

Kinetic energy (J) equation

1/2 x Mass (kg) x Velocity^2 (m/s)^2

Elastic potential energy (J) equation

1/2 x Spring Constant (N/m) x Extension^2 (m)^2

Efficiency equation

Useful energy output/total energy input x 100%

Power

Measures the rate at which work is done/the rate at which energy is transferred

Power (W) equation

Work done (J) / Time taken (s)