Question

For a projectile the range and maximum height are equal. The angle of projection is :

• A. ${45}^o$
• B. $0^o$
• C. ${76}^o$
• D. ${90}^o$

Answer 1

Answer: (C)

${76}^o$

In projectile thrown at angle $\theta$ Range $R$ and maximum height $H$ are given as :

Range, $R=\frac{u^2\left(\sin 2\theta \right)}{g}=\frac{u^{2}2\sin \theta \cos \theta }{g}$

Maximum Height, $H=\frac{u^2{\sin }^2\theta }{2g}$

Given: $H=R$

$\frac{u^2\left(2\sin \theta \cos \theta \right)}{g}=\frac{u^2{\sin }^2\theta }{2g}$

$4\cos \theta =sin\theta$

$\tan \theta =4$

$\theta ={76}^0$