A man can thrown a stone such that it acquires maximum horizontal range 80 m. The maximum height to which it will rise for the same projectile in metre is

Options

A. 10
B. 20
C. 40
D. 50

Answer

B

Explanation

`theta = 45^(@), R_(max) = (u^(2))/(g) = 80`
`:. u^(2) = 800 ms^(-2)`
Now, `H = (u^(2)sin^(2)45^(@))/(2g) = ((800)(1//2))/(20) = 20m`