Question

A stone is thrown at an angle Ф to the horizontal reaches a maximum height H. Then the time of flight of stone will be:
(answer should come                2√2H / √g  

Answer 1

R = u² sin 2Ф / g

H = u² sin² Ф / 2g        2Hg = u² sin² Ф

total time of flight is = 2 u sin Ф/g  =  2/g [ √2Hg ] = 2√(2H/g)