Question

What is a cool example of newtons 3rd law?

Answer 1

Newton's 3rd law is "For every action, there is an equal and opposite reaction" 

a "cool" example to describe this might be how fish swim or the impact from someone throwing a football.  

Answer 2

This law means that when one object exerts force on another, the same amount of force is exerted on the initial object, but in the opposite reaction. For example, when a billiard ball strikes another ball, the second ball is propelled forward. Simultaneously, the momentum of the first ball is slowed or stopped by opposing force. The amount that the first object is affected by the opposing force depends on the mass and motion of the second object.