Question

A projectile is thrown with velocity v making an angle `theta` with the horizontal. It just crosses the top of two poles,each of height h, after 1 seconds 3 second respectively. The time of flight of the projectile is
A. 2s
B. 6s
C. 8s
D. 4s

Answer 1

Correct Answer - D
`t_(OS)=1 sec`
`t_(OT)=3`
or `t_((ST))=t_((OT))-t_((OS))=3-1 =2 sec`
`:. T_((SM))=1/2 t_((ST))=1 sec`.
`:. T_((OM))=1/2 t_((OS))+t_((SM)) =1+1=2 sec`
`:. ` Time of flight 2x2=4 sec