A ball is projected vertically upwards with a certain initial speed. Another ball of the same mass is projected at an angle of `60^(@)` with the vertical with the same initial speed. At highest points of their journey, the ratio of their potential energies will be

Options

A. `1:1`
B. `2:1`
C. `3:2`
D. `4:1`

Answer

D

Explanation

`H_1 = u^2/(2g)`
`H_2=(u^2 sin^2 30)/(2g) =1/4 (u^2/(2g))`
PE = mgh , `PE prop h`
`((PE)_1)/((PE)_2)=1/(1//4)implies(PE)_1=4(PE_2)`