Question

The horizontal and vertical components of the velocity of projection of a projectile are $10{\text{ms}}^{-1}$ and $20{\text{ms}}^{-1}$ respectively. Find the horizontal range of projectile. ($g=10{\text{ms}}^{-2}$).

• A. $20\text{m}$
• B. $40\text{m}$
• C. $50\text{m}$
• D. $45\text{m}$

Answer 1

The correct option is B $40\text{m}$

Range of a projectile $=\frac{u^2\sin 2\theta }{g}$
$\Rightarrow R=\frac{2\left(u\sin \theta \right)\left(u\cos \theta \right)}{g}$
$R=\frac{2u_y{u}_x}{g}$
$=\frac{2\times 20\times 10}{10}$
$=40\text{m}$