Question

If a projectile is fired at an angle $\theta$ with the horizontal with velocity $u$, then the time of flight is given by :

• A. $\frac{ucos\theta }{g}$
• B. $\frac{usin\theta }{g}$
• C. $\frac{2usin\theta }{g}$
• D. $\frac{2ucos\theta }{g}$

Answer 1

Answer: (C)

$\frac{2usin\theta }{g}$

The time of flight of projectile will depend upon the vertical component of velocity , it will be twice the time its vertical component becomes zero due to gravity.
$0=usin\theta +(-g)tt=\frac{usin\theta }{g}$
Total time of flight $T=2t=\frac{2usin\theta }{g}$