Explain Newton's laws of motion

The first law is that an object will remain at a constant velocity or stationary (which is just a constant velocity of zero) unless acted upon by an external force.

Once acted upon by this force, then the second law comes into play. This says that F = ma, or Force equals mass times the acceleration of the object.

The third law is easily stated as every action has an equal and opposite reaction. This means the sizes of the forces on the objects will be the same, but the forces will be in opposite directions.