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

Answer 1

Answer: (C)

$h_1 = \frac{ h_2}{3} = \frac{h_3}{5}$

Answer 2

$h _{1}=\frac{1}{2} gt ^{2}=\frac{1}{2} \times 10 \times 5^{2}=125$
$h _{2}=\frac{1}{2} \times 10 \times 10^{2}-\frac{1}{2} \times 10 \times 5^{2}=375$
$h _{3}=\frac{1}{2} \times 10 \times 15^{2}-\frac{1}{2} \times 10 \times 10^{2}=625$
Hence $h _{1}=\frac{ h _{2}}{3}=\frac{ h _{3}}{5}$