Question

Find time of flight of a projectile thrown horizontally with speed $10m{s}^{-1}$ from a long inclined plane which makes an angle of $\theta ={45}^o$ with the horizontal (Take $g=10m{s}^{-2}$)

• A. $\sqrt{2}sec$
• B. $2\sqrt{2}sec$
• C. $2sec$
• D. $none$

Answer 1

The correct option is C $2sec$

$T=\frac{2vsin(\alpha +\beta )}{gcos\beta }$

Here, $\alpha =0$; $\beta ={45}^0$

$\therefore T=\frac{2u\sin \beta }{g\cos \beta }$

so time of flight will be, $T=\frac{20}{10}=2secs$