Forces

Velocity

The velocity of an object describes both the speed and direction of an object

Acceleration

The rate of change of velocity

Force

A push or a pull

Newton’s first law

An object will keep its same motion unless a net force acts on the object

Inertia

The property of an object that causes it to resist a change in its motion

Newton’s third law

For every force object A exerts on object B, object B will exert an equal force but in the opposite direction on object A

Resultant force/net force

The sum of all the forces acting on an object

Newton’s second law

F=ma

Vector

A physical quantity that has direction

Vector diagram

A line drawn to scale with an arrow to show direction

Contact force

When the object exerting the force and the object experiencing the force are touching

Frictional force

The force which opposes the motion of an object

Normal force

A support force exerted by a surface on an object which is touching it

Tension

A pull force which is experienced in ropes or strings

Compression

A pull force which is able to deform an object

Non-contact force

When the object exerting the force and the object experiencing the force do not have to touch

Field lines

Imaginary line drawn to show the strength and direction of non-contact forces

Gravitational force

The attractive force exerted on any object with mass

Weight

The force which the earth on any object which is on or near its surface

Magnetic force

An attractive or repulsive force experienced by magnets

Electrostatic force

Ab attractive or repulsive force experienced by charged objects

Mass

The amount of matter in an object

Free fall

The motion of an object when the only force acting on an object is the gravitational force of the earth

Gravitational acceleration

The acceleration an object experiences when the only force acting on it is the gravitational force

Terminal velocity

The max speed reached when an object falling to earth experiences equal forces up and down