A fighter plane flying horizontally at an altitude of 1.5 km with speed 720 km/h passes directly overhead an anti - aircraft gun . At what angle from the vertical should the gun be fired for the shell with muzzle speed `600"ms"^(-1)` to hit the plane ? At what minimum altitude should the pilot fly the plane to avoid being hit ? (Take g=`10 " ms "^(-2))`.

Answer

At an angle of `sin^(-1)(1//3)=19.5^(@)` with the vertical ; 16 km .