A jet plane flying at a constant speed v at an altitude h = 10 km is being tracked by ra...

A jet plane flying at a constant speed v at an altitude h = 10 km is being tracked by radar located at O directly below the line of flight. If the angle θ is decreasing at the rate of 0.020 rad/s when θ = 60^o, determine the value of at this instant and the magnitude of the velocity v of the plane.