Two particle A and B projected along different directions from the same point P on the ground with the same velocity of 70 m/s in the same vertical plane. They hit the ground at the same point Q such that PQ = 480,. Then `[g=9.8 m//s^(2)]`

Options

A. Ratio of their times of flight is `4 : 5`
B. Ratio of their maximum heights is `9 : 16`
C. Ratio of their minimum speeds during flights is `4 : 3`
D. The bisector of the angle between their directions of projection makes `45^(@)` with horizontal

Answer

B, C, D

Explanation

Range `=(u^(2)sin 2theta)/(g)rArr 480=4900/980xxsin 2theta`
`(90-theta)` projection angle has sme range. ltbtgt time of flight :
`T_(1)=(2u sin theta)/(g), T_(2)=(2u sin(90-theta))/(g)`