Question

A stone falls freely under gravity. It covers distances $h_1,h_2$ and $h_3$ in the first 5 seconds, the next 5 seconds and the next 5 seconds respectively. The relation between $h_1,h_2$ and $h_3$ is :-

• A. $h_1=h_2=h_3$
• B. $h_1=2h_2=3h_3$
• C. $h_1=\frac{h_2}{3}=\frac{h_3}{5}$
• D. $h_2=3h_1$ and $h_3=3h_2$

Answer 1

Answer: (C)

$h_1=\frac{1}{2}g{t}^2=\frac{1}{2}\times 10\times 5^2=125$
$h_2=\frac{1}{2}\times 10\times 10^2-\frac{1}{2}\times 10\times 5^2=375$
$h_3=\frac{1}{2}\times 10\times 15^2-\frac{1}{2}\times 10\times 10^2=625$
Hence $h_1=\frac{h_2}{3}=\frac{h_3}{5}$