Question:
An NCC parade is going at a uniform speed of $6 \mathrm{~km} / \mathrm{h}$ through a place under a berry tree on which a bird is sitting at a height of $12.1 \mathrm{~m}$. A particular instant the bird drops a berry. Which cadet (give the distance from the tree at the instant) will receive the berry on his uniform?
Solution:
For berry,
$u=0 ; a=g ; s=12.1 m$
$\mathrm{s}=\mathrm{ut+}{ }^{\frac{1}{2}} a \mathrm{t}^{2}$
$12.1=0+\frac{1}{2}(g) t^{2}$
$\mathrm{t}=1.57 \mathrm{sec}$
Distance moved by cadets $=\mathrm{v} \times \mathrm{t}$
$=\left(6^{\times \frac{5}{18}}\right)(1.57)$
$=2.6 \mathrm{~m}$
The cadet, $2.6 \mathrm{~m}$ away from tree will receive berry on his uniform