In the previous lesson, you have studied about the motion of bodies in a straight line. You have learnt that there are three equations of motion, with the help of which you can solve problems involving initial velocity, duration of motion and the acceleration with which a body travels. But what is the cause of change in motion or cause of acceleration which is responsible for producing an increase in the velocity of a moving body? Newton formulated three laws regarding the motion of bodies. These laws are called Newton’s laws of motion. In this lesson you will learn about these laws. These laws will tell you why a motion occurs. These will help you to find out more about moving bodies.
If you push a body on a floor or ground, the body stops after moving through some distance. Why does it happen so? Why does a stone thrown upwards always come down to the earth? Why the edge of a knife is made sharp? Why do some bodies float on water whereas some other bodies sink in water? The answer to such questions will be discussed in the present lesson.