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 [tex]h_0[/tex] above window
let t be the time to cover [tex]h_0[/tex]
[tex]h_0+1=\frac{g(t+0.28)^2}{2}[/tex]------1
[tex]h_0=\frac{gt^2}{2}[/tex]--------2
subtract 1 & 2
[tex]1=\frac{g(t+0.28)^2}{2}-\frac{gt^2}{2}[/tex]
[tex]1=\frac{g}{2}\left [ \left ( 2t+0.28\right )\left ( 0.28\right )\right ][/tex]
t=0.224 s
[tex]h_0=\frac{9.8\times 0.224^2}{2}[/tex]
[tex]h_0=0.246 m[/tex]