Physics 11 – Today in physics we formalized Newton’s 3rd Law. Students had already worked out equal and opposite forces when discussing gravity, but we didn’t put a name to it or generalize it to all forces. We also watched a video of two carts colliding, where each cart had a steel hoop attached to the front. When they collide, the hoops on both carts compress the same amount. By recalling Hooke’s Law, the students reasoned that since the compression was the same, the forces had to be the same.