A bullet is to be fired with a speed of `2000 m//s` to hit a target `200 m` away on a level ground. If `g = 10 m//s^(2)`, the gun should be aimed

Options

A. Directly at the target
B. `5 cm` below the target
C. `5 cm` above the target
D. `2 cm` above the target

Answer

C

Explanation

`R = (u^(2))/(g) sin 2theta rArr 200 = ((2000)^(2))/(10) sin 2 theta`
`sin 2 theta = (1)/(2000), 2 theta = (1)/(2000) rArr theta = (1)/(4000)`
(`theta` is very small)
`tan theta = theta = (h)/(200) rArr (1)/(4000) = (h)/(200)`
`h = (1)/(20)m = 5 m`