I checked and and briefly discussed the reading and questions from the textbook. I emphasized that all forces come in pairs that are equal and opposite in value. The Third Law pair for all objects can be determined fairly easily using the force naming terminology we developed in the first unit. For example, for a book sitting on the table, we can look at the gravity force as the Force of Earth on the book. The third law pair of this would be the Force of Book on Earth. I also did a demonstration using the force sensors to prove that in all interactions, the forces are equal and opposite.
We then moved on to the impulse-momentum equation as it is derived from Newton's second law. I did a demo with an egg dropping on the floor vs. begin thrown at a sheet. In one scenario, the egg is moving slow and the egg breaks, in the other it is moving very fast, but doesn't break. Clearly the change in momentum of the pitched egg is greater than the dropped egg, yet more force was applied on the egg that was moving slower, so it broke. We will discuss this concept in greater detail next time.
HW: Finish WS 5-1; WS 1 and any other class work that you didn't finish.
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