Mechanics

Chapter 7

Newton's Third Law of Motion

7.1 A SLIDE SHOW ON NEWTON'S THIRD LAW OF MOTION

1. Newton's first and second laws tell us that a body accelerates due to external forces. The net external force equals the mass of the body times its acceleration. These laws do not tell us where this force comes from. Does the force that drives this car come from the engine?

    

   

    

2. If so, why is this car stuck on wet clay road when the engine is running in full throttle? The force that pushes the car forward does not come from the engine. This force comes from the road due to friction between the tyre and the road, and is called traction.

    

    

3. Does the force ...