0-kg projectile is fired at an angle of 30.0 above the horizontal with an initial speed of 105 m/s from the top of a cliff 164 m above level ground,...

A 44.0-kg projectile is fired at an angle of 30.0° above the horizontal with an initial speed of 105 m/s from the top of a cliff 164 m above level ground, where the ground is taken to be y = 0. Suppose the projectile is traveling 85.0 m/s at its maximum height of y = 272 m. How much work has been done on the projectile by air friction?