MOTION

4. NEWTON'S LAW OF MOTION

3.0 Introduction

Isaac Newton was a brilliant scientist who helped explain how things move on Earth and in space. His three laws of motion changed the way people understood the physical world. By building on the ideas of earlier scientists like Galileo and Kepler, Newton demonstrated that motion can be predicted using mathematical principles. His discoveries marked a major shift from old ways of thinking to modern science.

Forces are what cause objects to move. A force can be a push or a pull, like when you push a door open or when gravity pulls an object down. Some forces are strong, like a cannon firing a cannonball, while others are weak, like a mosquito landing on your arm. When multiple forces act on an object, they combine to create a net force, which determines how the object moves. If forces push in opposite directions, the more potent force will win out. Scientists use a system of positive and negative signs to keep track of forces and movement, making calculations easier and more accurate.

Newton’s laws help explain motion everywhere, from a ball rolling on the ground to a satellite orbiting Earth. Forces can come from inside a system (internal forces) or from outside (external forces). For example, when an object hangs from a rope, the force of gravity pulls it down while the rope pulls it up, keeping it in place. Understanding these forces helps us predict how objects will move, making Newton’s laws essential to physics and engineering.