Newton's Laws of Motion

Newton's laws of motion are three physical laws that describe the relationship between the forces acting on a body and its motion due to those forces.

First law:

The velocity of a body remains constant unless the body is acted upon by an external force.

A body at rest will remain at rest and a body in motion will remain in motion unless acted upon by an outside force.

Second law:

The acceleration (a) of a body is parallel and directly proportional to the net force (F) and inversely proportional to the mass (m), i.e., (F = ma).

A greater force will cause more acceleration.  A smaller force will cause less acceleration.  A smaller mass will accelerate with less force.  A larger mass will accelerate with more force.

Third law:

The mutual forces of action and reaction between two bodies are equal, opposite and collinear.

For every action there is an equal and opposite reaction.