Question

At some planet, $g=1.96m{s}^{-2}$. If it is safe to jump from a height of $2m$ on earth, then the corresponding safe height on that planet is

• A. $2m$
• B. $5m$
• C. $10m$
• D. $20m$

Answer 1

Answer: (C)

$10m$

Gravitation potential on the planet$,P.E{.}_P=mg{h}_P$
$\Rightarrow P.E{.}_P=m\times 1.96h_P$
Gravitation potential on the earth$,P.E{.}_E=mg{h}_E$
$\Rightarrow P.E{.}_E=m\times 9.8\times 2$
$\Rightarrow P.E{.}_E=P.E{.}_E$
$\Rightarrow m\times 1.96h_P=m\times 9.8\times 2$
$\Rightarrow h_P=\frac{m\times 9.8\times 2}{m\times 1.96}=10m$