2 Who was Isaac Newton?Sir Isaac Newton was a mathematician and physicist. He is considered to be the greatest and most influential scientist who ever lived. He was born and raised in Lincolnshire, England.25 December 1642 – 20 March 1727
3 Why is Isaac Newton so well known? Newton described universal gravitationNewton described the three laws of motionNewton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws
4 Universal Gravitation Prior to Newton and Galileo, most people thought that the forces causing motions on Earth and the forces causing the stars and planets to move were different forces. Isaac Newton realized that the same forces and the same laws of physics apply everywhere in the universe. So, his law of gravity is called the law of universal gravitation.
5 Newton’s first law of motion An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. This law is often called “the law of inertia”.
6 Newton’s second law of motion Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object). This can be expressed as a mathematical equation. F = M x A, or Force is equal to mass times acceleration.
7 Newton’s third law of motion For every action, there is an equal opposite reaction. This means that for every force there is a reaction force that is equal in size, but opposite in direction. That is to say that whenever an object pushes another object it gets pushed back in the opposite direction equally hard.The rocket's action is to push down on the ground with the force of its powerful engines, and the reaction is that the ground pushes the rocket upwards with an equal force.
8 Therefore,First law: The speed in a given direction of a body remains constant unless the body is acted upon by an external force.Second law: The acceleration of a body is parallel and directly proportional to the force and inversely proportional to the mass, i.e., F = M x A.Third law: The mutual forces of action and reaction between two bodies are equal, opposite and collinear.