

Newton's three laws of motion 
Newton's first law Every object in a state of uniform motion tends to keep its state of motio,n unless an external force is applied to it 
This can be recognized as Galileo's concept of inertia, and is therefore often called Law of inertia
The second law of motion: The relation between the mass m, the acceleration and the force applied to a body is: 
The basic concept of this second law is the determination of how much velocities change when forces are applied. This is the most powerful of Newton's laws, allowing quantitative calculations of dynamics.
Newton's third law For every action there is an equal and opposite reaction 