- #1
B3NR4Y
Gold Member
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Homework Statement
During a blackout, you are trapped in a tall building. You want to call rescuers on your cell phone, but you can't remember which floor you're on. You pry open the doors to the elevator shaft, drop your keys down the shaft, and hear them hit bottom at ground level 3.27 s later. Assume that the height of one floor is 3.0 m.
Homework Equations
[itex] d=\vec{v}_{i} t - \frac{1}{2} g t^{2} [/itex]
(I directed my coordinate system so that down is in the negative direction.)
The Attempt at a Solution
I first write everything I know
vi = 0 m/s (because you start at rest)
g = 9.8 m/s2
t = 3.27 s
I put this all into the equation and get the height of the building to be 52.395 m tall. Which I then divided by 3 to get the floor we're on, the 17th floor. This is wrong.