An ice rink givesus a good opportunity to think about forces and momentum. Consider two identical hockey pucks, A and B. Puck A is in motion travelling in the positive

direction towards Puck B which is at rest. The ice surface is frictionless, so there are no resistive forces acting on the either puck. Puck A strikes Puck B. How does the force Puck A imparts on B compare to the force Puck B imparts on A? The force Puck A imparts on Puck B is the force Puck B imparts on Puck A.Which big idea from Unit 1 best explains your answer?