Physics Science Revision

Revision

A force

A push or a pull

Two types of forces

Contact and non-contact

Law of Intertia

Balanced forces stay still or at constant motion until unbalanced by another force

Unit of forces

Newtons

Forces mediated by fields (non-contact)

Gravitational, electric, and magnetic forces

Contact forces

Applied, normal, frictional, air resistance, tension, springs, and buoyant forces

Normal/support

Force that a surface places on an object

Gravity/weight

Acts from the centre of mass downwards towards the centre of the earth on an object

Air resistance

Acts to oppose the motion of a object, the air pressure that acts on an object

Support/Normal

The force that a surface places on an object, pushing against it

Buoyancy

The upward force from water

Thrust

The force of an engine on an object

Magnetic

Attraction or repulsion between magnets

Elastic restoration

The force from a spring

Balanced forces

Objects’ forces are all balanced and remains stationary/at constant speed. Fnet = 0

Unbalanced forces

Objects’ forces are unbalanced and accelerate, change speed, or direction.

Friction

Force exerted by a surface, opposing the moving object

Newton’s Second Law

The force applied to an object is equal to its mass times acceleration (Fnet = Mass*Acceleration)

Mass

How much matter is in something

Weight

The force put onto something due to gravity. Measured in Newtons

Rule for finding weight

W = mass*gravity

Newton’s 3rd Law

For every action, there is an equal and opposite reaction. When ‘A’ puts a force on ‘B’, ‘B’ puts an equal and opposite force on ‘A’

Rule for finding Speed, Velocity (V)

V = Distance/Time

Distance-Time graphs

Shows the speed at any time during a journey

Rule for finding total forces

Fnet = mass*acceleration

The Law of Conservation

Energy cannot be created or destroyed, it only changes form and be transformed from one object to another

Joule (J)

The unit used to quantify energy & work done

Kinetic

Energy possessed by an object due to its motion

Potential

Stored energy waiting to be released due to state, position, or chemical bonds

Conservation

The principle that total energy in an isolated system remains constant over time