Question

A body falling from a high Minaret travels 40 meters in the last 2 seconds of its fall to ground. Height of Minaret in meters is (take $g = 10m/s^{2}$)

• A. 60
• B. 45
• C. 80
• D. 50

Answer 1

Answer: (B)

45

Answer 2

Let height of minaret is H and body take time T to fall from top to bottom.

$H = \frac{1}{2}gT^{2}$ …(i)

In last 2 sec. body travels distance of 40meter so in $(T - 2)$ sec distance travelled $= (H - 40)\mspace{6mu} m$

$(H - 40) = \frac{1}{2}g(T - 2)^{2}$ …(ii)

By solving (i) and (ii) $T = 3$sec and$H = 45\mspace{6mu} m$.