Question

A boy can thrown a stone up to a maximum height of $10$ m. The maximum horizontal distance that the boy can throw the same stone up to will be:-

• A. 20 m
• B. $20\sqrt{2}$
• C. 10 m
• D. $10\sqrt{2}$

Answer 1

The correct option is A 20 m

Maximum height $=10$ meters

using the equation $v^2=u^2+2as$, where

$v=$Final velocity at maximum height $=0m/s$

$u$ = Initial velocity

$a=10m/s^2\left(Downwards\right)$

$S=10meters$

Taking downward direction as negative

$v^2=u^2+2aS$

$0=u^2+2(-10)\left(10\right)$

$u^2=200$

$u=10\sqrt{2}m/s$

Maximum Range is when angle of projection is ${45}^{\circ }$

$\theta$ = Angle of Projection

Range = $\frac{u^2\sin 2\theta }{g}$

$=\frac{200\times \sin \left({90}^{\circ }\right)}{10}$

$=\frac{200}{10}$

$=20meters$

therefore Correct option is (A) that is 20 meters.