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

Options

A. `sin^(-1) (1/3), 16 km `
B. `cos^(-1)(1/3) , 18 km `
C. `sin^(-1)(1/3), 6 km `
D. `cos^(-1)(1/3) , 6 km`

Answer

A