Question

Obtain an expression for Time of flight of a projectile.

Answer 1

Consider a projectile fired with velocity $V$ at an angle $\theta$ with horizontal.

From equations of motion we write $y=ut+\frac{1}{2}{at}^2$

Here, final displacement in $y$ direction $=0$

$\Rightarrow O=V\sin \theta .t-\frac{1}{2}{gt}^2$

$\Rightarrow 2V\sin \theta =gt$ or $t=\frac{2V}{g}sin\theta$ $\to$ Time of flight.