A fighter plane enters inside the enemy territory, at time `t=0`, with velocity `upsilon_(o)=250m//s` a moves horizontally with constant acceleration `a=20m//s^(2)` (see figure) An enemy tank at the border, spot the plane and fire shots at an angle `theta=60^(2)` with the horizontal and with velocity `u=600 m//s`.At what altitude `H` of the plane it can be hit by the shot?

Options

A. 1500m
B. 2473m
C. 1650m
D. 1800m

Answer

b

Explanation

If it is being hit then `d=v_(0)t+(1)/(2)at^(2)=(u cos theta)t`

or `t=(u cos theta-v_(0))/(a//2)`
`therefore t=5s`
`H=(u sin theta)t-(1)/(2)g t^(2)`
`H=1500sqrt(3)-125`
`rArr H=2473m`