This week in physical science we will be discussing action-reaction force pairs, so famously summarized by one form of Newton’s Third Law: For every action there is an equal and opposite reaction. In physics we describe this it a little more precisely: For every force, there is a corresponding reaction force equal in magnitude and opposite in direction. This phenomenon is readily apparent in the “kick” of a firearm, the force one feels when catching a ball, or in the forward push a watercraft receives from a paddle-stroke. It is also what allows a rocket’s engine to provide thrust, even in space where there is seemingly nothing to “push” against.
For 10 points of extra credit, students can turn in the following by Tuesday:
Draw the free body diagram for the bottom textbook in a stack of textbooks resting on a table. Be sure to correctly label all of your forces, but you need not calculate their magnitude. Also include your axis labels.