A plane flying horizontally at a height of 1500 m with a velocity of 200 ms⁻¹ passes directly overhead an antiaircraft gun. Then the angle with the horizontal at which the gun should be fired for the shell with a muzzle velocity of 400 ms⁻¹ to hit the plane, is -
Options

Question

A plane flying horizontally at a height of 1500 m with a velocity of 200 ms⁻¹ passes directly overhead an antiaircraft gun. Then the angle with the horizontal at which the gun should be fired for the shell with a muzzle velocity of 400 ms⁻¹ to hit the plane, is -

Options

G1 Physics · Accepted Answer

For the shell to meet the plane, their horizontal velocities must be equal because both start vertically above the same point and the plane moves at 200 m/s. Hence 400cosθ = 200, so cosθ = 1/2 and θ = 60°. Therefore option B.