If a stone is to hit at a point which is at a distance `d` away and at a height `h` (see fig) above the point from where the stone starts,then what is the value of initial speed `u` if the stone is launched at an angle `theta`?

Options

A. `d/sinthetasqrt(g/(2(d tan theta-h))`
B. `d/costhetasqrt(g/(2(d tan theta-h))`
C. `sqrt((gd)/(h cos ^(2)theta)`
D. `sqrt((gd)/((d-h))`

Answer

B

Explanation

`h=(u sin theta)t-1/2"gt"^(2),d=(u cos theta)t`