Summary of Newton's Laws of Motion

Newton's Laws of Motion

First Law (Law of Inertia)

• An object at rest stays at rest; an object in motion stays in motion with the same speed and direction unless acted upon by an unbalanced force.

• Inertia is the tendency of objects to resist changes in their state of motion.

Second Law

• Acceleration ($a$) of an object is directly proportional to the net force ($F$) acting on it and inversely proportional to the object's mass ($m$):

  • $F = m imes a$

• The greater the force applied, the greater the acceleration.

Third Law

• For every action, there is an equal and opposite reaction:

  • Forces between interacting bodies are equal in magnitude but opposite in direction.