A person is standing on an open car moving with a constant velocity of `30 m//s` on a striaght upward direction and it returns to person after the car has moved `240 m`. The speed and the angle of projection

Options

A. as seen from the car is `40 m//s`, `90^(@)`
B. as seen from the road is `50 m//s`, `tan^(-1)(4//3)`
C. both (1) and (2)
D. none

Answer

C

Explanation

`x: 240 = 30 t = rArr t = 8 s`
`y`: `t = (2 u')/(g) rArr 8 = (2 u')/(10) rArr u' = 40 m//s`
For the observer on the road:

`u = sqrt((30)^(2) + (40)^(2)) = 50 m//s`
`tan theta = (40)/(30) rArr theta = tan^(-1)(4//3)`
For the observer on the car: