Newton's Third Law To every action there is always opposed an equal reaction: or, the mutual actions of two bodies, each upon the other, are always equal and directly opposed.3 Think of it like this: as you drive down the road your tires are rotating backwards on the road pushing it behind the car and the road is in turn pushing the car tires forward. The force the car puts on the road is equal to the force the road  puts on the car tires.5                                                                                                                            (The above picture was taken from http://www.vincecrain.com/chevypage.html)