Isaac Newton figured out the laws of motion through patient observation. Newton's three laws of motion describe the relationship between an object and the forces acting on it. Newton's first law states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. Newton's second law states that the greater the mass of an object, the greater the amount of force needed to accelerate it. Newton's third law states that for every action, there is an equal and opposite reaction.