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

A 48 kg passenger rides in an elevator that starts from rest on the ground floor of a building at t = 0 and rises to the top floor during a 10 s interval. The acceleration of the elevator as a function of the time is shown in Fig. 3-32, where positive values of the acceleration mean that it is directed upward. Give the magnitude and direction of the following forces.

Fig. 3-32 (in words)

-max positive acceleration = 2 m/s^2 at t = 2 s

-max negative acceleration = -3 m/s^2 at t = 8.5 s

-0 acceleration from 4 s to 7 s

(a) the maximum force on the passenger from the floor

(b) the minimum force on the passenger from the floor

(c) the maximum force on the floor from the passenger

2. Relevant equations

F = ma

3. The attempt at a solution

For part a), I thought it would just be F =(48kg)(2), but that was not correct. I know it's in an upward direction, but I can't seem to find the magnitude.

Part b) I figured that the minimum force should be when the acceleration = 0, so I tried F=(48)(0) = 0. But it just doesn't seem logical to me...

Part c) I think the maximum force should be when a = -3, but I plugged it into the formula and it was not correct.

Any help would be appreciated, thanks!

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# Homework Help: Riding the elevator

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