Energy, Matter, Forces and Motion Vocabulary

Key vocabulary terms, definitions, principles, and equations covering energy stores, energy transfers, work, moments, and elasticity from Key Stage Three Science notes.

Gravitational Potential Energy Store

The store of energy possessed by anything in a gravitational field that can fall; the higher it goes, the more energy it has.

Chemical Energy Store

The store of energy held by anything with energy that can be released through a chemical reaction, such as food, fuels, and batteries.

Kinetic Energy Store

The store of energy present in anything that moves.

Elastic Potential Energy Store

The store of energy present in anything that is stretched or compressed, such as rubber bands and springs.

Magnetic Energy Store

The store of energy created by two magnets that attract or repel each other.

Thermal Energy Store

The store of energy possessed by all objects; the hotter an object is, the higher its temperature and the more energy it holds in this store.

Electrostatic Energy Store

The store of energy created by two electric charges that attract or repel each other.

Mechanical Energy Transfer

A pathway of energy transfer that occurs when a force makes something move by pushing, pulling, stretching, or squashing it.

Electrical Energy Transfer

A pathway of energy transfer that occurs when electric charges move around an electric circuit due to a potential difference.

Energy Transfer by Heating

A pathway of energy transfer where energy moves from hotter objects to colder objects.

Energy Transfer by Light and Sound

A pathway of energy transfer where light or sound waves carry energy from one place to another.

Metabolised

Changed during chemical processes inside the body to release the energy contained in food.

Energy Transferred Equation

The mathematical relationship calculating energy transferred via a force: $\text{Energy Transferred (J)} = \text{Force (N)} \times \text{Distance (m)}$.

Principle of Conservation of Energy

The scientific principle stating that energy can never be created nor destroyed; it is only ever transferred from one store to another.

Total Energy Input Equation

The rule stating that the total energy supplied to a device equals the sum of its outputs: $\text{Total Energy Input} = \text{Useful Energy Output} + \text{Wasted Energy}$.

Energy Transfer Diagram

A diagram that shows how energy moves between stores using rectangles for stores and labeled arrows for transfer methods.

Force Diagram

A diagram that illustrates the forces acting on an object and indicates whether those forces are balanced or unbalanced.

Balanced Forces

Forces acting on an object that are equal in magnitude and opposite in direction, resulting in an overall force of $0\,\text{N}$ so that the object stays stationary or moves at a steady speed.

Unbalanced Forces

Forces acting on an object that are unequal in magnitude, causing the object to accelerate or decelerate in the direction of the larger force.

Pivot

The central point around which rotation happens, such as the middle of a seesaw.

Moment

The turning effect produced by a force acting on an object with a pivot.

Moment Equation

The equation used to calculate the turning effect of a force: $\text{Moment (Nm)} = \text{Force (N)} \times \text{Perpendicular Distance (m)}$, or $M = F \times d$.

Balanced Moments

A state where total rotational turning effects cancel out, given by the rule: $\text{Anticlockwise Moments} = \text{Clockwise Moments}$.

Deform

To change the shape of an object by applying forces to stretch or compress it.

Elastic

The property of a material or object that allows it to return to its original shape after the deforming force is removed.

Hooke's Law

The principle stating that the extension ($e$) of a spring is directly proportional to the applied force ($F$), expressed as $F = k \times e$.

Spring Constant ($k$)

A measure of stiffness that depends on the specific material being stretched, measured in newtons per metre ($\text{N/m}$).

Equilibrium

The state in which all opposing forces acting on an object are completely balanced.