A cannon fires successively two shells with velocity vo = 250 m/s; the first at the angle 1 = 60 and the second at the

A cannon fires successively two shells with velocity vo = 250 m/s; the first at the angle θ1 = 60° and the second at the angle θ2 = 45° to the horizontal, the azimuth being the same. Neglecting the air drag, find the time interval between firings leading to the collision of the shells