Energy P1 - Definitions

Kinetic Energy

Energy an object has because it is moving

Gravitation Potential Energy

Energy an object has because of its height above the ground

Elastic Potential Energy

Energy an elastic object has when it is stressed or compressed

Thermal Energy (Internal Energy)

Energy an object has because of its temperature (The total kinetic and potential energy of the particles in the object)

Chemical Energy

Energy that can be transferred by chemical reactions involving foods, fuels and the chemicals in batteries

Nuclear Energy

Energy stored in the Nucleus of an atom

Magnetic Energy

Energy a magnetic object has when it is near a magnet or magnetic field

Electrostatic Energy

Energy a charged object has when its near another charged object

System

An object or a group of objects

Closed System

A system where no energy can escape to or enter from the surroundings. The total energy in a closed system never changes

Heating

Energy is transferred from one object to another object with a lower temperature

Waves

Waves can transfer energy

Forces (Mechanical)

Energy is transferred when a force moves or changes the shape of an object

Electricity

An electric current transfers energy

Dissipated

Energy is wasted, or transferred to less useful stores

Lubrication

A way of reducing unwanted energy transfer due to friction

Streamlining

A way of reducing energy wasted due to air resistance or drag in water

Efficiency

A measure of how much energy is transferred usefully. If a motors energy is 30% efficient, the motor is 30% efficient

Work Done

Energy transferred when a force moves an object

Power

How much work is done (or how much energy is transferred) per second. The unit of power is Watt (W)

Directly Proportional

As one quantity increases, the other increases at the same rate

Elastic Limit

The point where an elastic object breaks or snaps

Hooke’s Law

The extension of an elastic object is directly proportional to the force applied, up to the elastic limit

Spring Constant (k)

Spring constant is a measure of how easy it is to stretch or squash an object. It’s symbol is k

Energy transfer

How energy can be transferred to and from stores. It could be transferred by: Heating, Waves, Electricity, Forces (mechanical work)