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

A box falls from an elevator that is ascending with a velocity of 2 m/s. It strikes the bottom of the elevator shaft in 3 seconds. A) How long will it take the box to reach its maximum height?

B) How far from the bottom of the shaft was the box when it fell off the elevator? C) What is the height of the elevator when the box is at its highest point?

2. Relevant equations

v(t) = v0 + at

x(t) x0+v0t+1/2at^{2}

v^{2}-v0^{2}=2aΔx

3. The attempt at a solution

I know that the elevator will reach a maximum height when the velocity is 0. So v = 0, v0 = 2 m/s, a = 9.8 m/s^{-2}, t=3 sec.

For A) (the one I'm concerned with for now), I set it up as V-V0/a = t. Plugging everything in, t = 0 - (2 m/s)/9.8 m/s^{-2}to get an answer of -.204 s. I know that must not be right as I don't believe t can be negative. However, since the box is falling off the elevator, shouldn't it be measured as a positive value since it's falling down?

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