Newtons laws of motion

Newton's First Law

An object remains in the same state of motion unless a resultant force acts on it

Resultant force

A single force that has the same effect as the original forces on an object acting together

When the resultant force is zero

A stationary object stays stationary and moving object continues to move at the same speed and in the same direction

Newton's Second Law

The acceleration of an object is proportional to the resultant force acting on the object, and inversely proportional to the mass of the object

F \= ma

The equation linking resultant force, mass and acceleration

F

The symbol for force

m

the symbol for mass

a

The symbol for acceleration

Newtons (N)

The SI unit for force

Kilograms (kg)

The SI unit for mass

Metres per second squared (m/s²)

The SI unit for acceleration

Newton's Third Law

Whenever two objects interact, the forces they exert on each other are equal and opposite

Inertia

The tendency of an object to continue in their state of rest or of in uniform motion (not accelerating)

Inertial mass

A measure of how difficult it is to change the velocity of an object or the ratio of force over acceleration