Question

A roof tile falls from rest from the top of a building. An observer inside the building notices that it takes 0.28 s for the tile to pass her window, which has a height of 1.0 m. How far above the top of this window is the roof?

Answer 1

Answer:0.246 m

Explanation:

Given

height of window (h)=1 m

Time to pass window =0.28 s

Let roof is at a distance of $h_0$ above window

let t be the time to cover $h_0$

$h_0+1=\frac{g(t+0.28)^2}{2}$------1

$h_0=\frac{gt^2}{2}$--------2

subtract 1 & 2

$1=\frac{g(t+0.28)^2}{2}-\frac{gt^2}{2}$

$1=\frac{g}{2}\left [ \left ( 2t+0.28\right )\left ( 0.28\right )\right ]$

t=0.224 s

$h_0=\frac{9.8\times 0.224^2}{2}$

$h_0=0.246 m$