From the top of a building `80 m `high, a ball is thrown horizontally which hits the ground at a distance.The line joining the top of the building to the point where it hits the ground makes an angle of `45^(@)` with the ground. Initial velocity of projection of the ball is `(g=10 m//s^(2))`

Options

A. `10 m//s`
B. `15 m//s`
C. `20 m//s`
D. `30 m//s`

Answer

C

Explanation

`h=R=usqrt((2h)/g)`