(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Henry gets into an elevator on the 50th floor of a building and it begins moving at t=0s. The figure shows his apparent weight over the next 12 seconds.

Part A: Is the elevator's initial direction up or down? Explain how you can tell.

Part B: What is Henry's mass?

Part C: How far has Henry traveled at t=12s?

2. Relevant equations

F=ma

F=m(g + ay)

3. The attempt at a solution

Part A:

The elevator is initially going in the downward direction. This is because the apparent weight stays the same for 2 seconds if it went upwards the apparent weight would have gone up right then starting from t=0.

Part B:

First I just did F=ma at 600N because that was the start...so 600N=mg. m came out to be 61.22kg. This was incorrect.

Then I thought that whenever there is an apparent weight change that is when the elevator switches direction because it has to break equilibrium in the forces to switch the net forces direction. So I suppose that since the apparent weight is 750N mostly I put that in force and it was: 750N=mg so m= 76.53kg

Part C:

Im not sure how to do this. I suppose there is some relation between apparent weight change and acceleration? like Fnet=ma and the a will be the acceleration for the direction change?

The only thing is the image does not show how long the acceleration is for.

please help for B and C

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Elevator Problem Apparent weight and distance traveled!

**Physics Forums | Science Articles, Homework Help, Discussion**