Two projectile are projected with the same velocity. If one is projected at an angle of `30^(@)` and other at `60^(@)` to the horizontal. The ratio if maximum heights reached, is:

Options

A. `3:1`
B. `1:3`
C. `1:2`
D. `2:1`

Answer

B

Explanation

(b): For angle `theta=30^(@)` , maximum height `H_(1)` is
`H_(1)=(u^(2)sin^(2)30^(@))/(2g)`
other projected at an angle `theta=60^(@)` . Maximum height `H_(2)` is
`h_(2)=(u^(2) sin ^(2)60^(@))/(2g)`
`(H_(1))/(H_(2))=(sin ^(2)30^(@))/(sin^(2)60^(@))=((1)/(2))^(2)xx((2)/(sqrt3))^(2)`
`(H_(1))/(H_(2))=(1)/(2)`
`H_(1):H_(2)= =1:3`