Question

A boy can throw a stone up to maximum height of 10 m. Upto which maximum distance in horizontal direction, can he throw the same stone?

Answer 1

Correct option is : (d) 20 m

For maximum height, if velocity is u, then

\(u = \sqrt{2gh} = \sqrt{2\times10\times10} = 10\sqrt{2}\ ms^{-1}\)

For R_max, θ = 45°

\(\therefore\ R_{max} = \frac{u^2\sin2\theta}{g} = \frac{u^2\sin90^\circ}{g} = \frac{u^2}{g}\) 

\( = \frac{(10\sqrt{2})^2}{10} = \frac{10\times10\times2}{10} = 20\ m\)

or R_max = 20 m

Thus, option (d) is correct.