#3 asked about our previous "elevator" problem. It stated that a person that was in an elevator was applying a force down, and his weight increased as the elevator went up, and decreased when he reached the top. This is due to the acceleration of both the elevator and the person. On the way up, the acceleration is 2.5 m/s/s. When the man reaches the top, the acceleration is -3.0 m/s/s. He is less wegith because the unbalanced forces are pulling down at the top causing an opposite acceleration and causing him to only feel the normal force at that instant from the elevator, not gravity.
#4 was about how much an elevator can hold. It can hold 30000 n of force without the cable snapping. It can hold 20 people of 75kg. The elevator weighs 500kg. The cable pulls at 30000n and the force of the people and the elevator pulled down by gravity is 20000 n. The total unbalanced force is 10,000n. The wieght of the people plus the elevator is 2000kg, so you take Funbal/mass=A. You do this and find that the elevator can accelerate at a maximum of 5m/s/s without the cable snapping.
Then we started some truck problem where harry potter was making a ball float. It doesnt make sense. So don't count on me!
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