2. Newton’s 3 rd Law Action-Reaction Forces

3. For every action, there is an equal and opposite reaction. According to Newton, whenever two objects interact with each other, they exert forces upon each other. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects.

4. in a chair your body exerts a downward force on the chair the chair exerts an upward force on your body two forces resulting from this interaction a force on the chair a force on your body the two forces are called action and reaction forces

5. size of the force on the first object equals the size of the force on the second object direction of the force on the first object is opposite to the direction of the force on the second object forces always come in pairs equal and opposite action-reaction force pairs

6. Consider the propulsion of a fish through the water fish uses fins to push water backwards a push on the water will only serve to accelerate the water water reacts by pushing the fish forwards, propelling the fish through the water size of the force on the water equals the size of the force on the fish direction of the force on the water (backwards) is opposite the direction of the force on the fish (forwards)

7. Consider the motion of a bus on the way to school. bus is equipped has wheels that turn wheels turn and grip the road and push the road backwards road reacts by pushing wheels forward size of the force on the road equals the size of the force on the wheels (or bus); the direction of the force on the road (backwards) is opposite to the direction of the force on the wheels (forwards)

8. While driving down the road, an unfortunate bug strikes the windshield of a bus. Quite obviously, this is a case of Newton's third law of motion. The bug hit the bus and the bus hits the bug. Which of the two forces is greater, the force on the bug or the force on the bus?

9. TRICK QUESTION! The forces are equal. The bug gets squashed because it isn’t built to withstand the acceleration.