Question

A monkey can jump a maximum horizontal distance of $20m$. Then the velocity of the monkey is

• A. $10m{s}^{-1}$
• B. $14m{s}^{-1}$
• C. $20m{s}^{-1}$
• D. $24m{s}^{-1}$

Answer 1

Answer: (B)

$R=\frac{u^2\sin 2\theta }{g}$
$R_{\max }=\frac{u^2}{g}$ when $\theta =45^{\circ }$
$\Rightarrow 20m=\frac{u^2}{9.8}$
$u=(20\times 9.8{)}^{\frac{1}{2}}=14m{s}^{-1}$