Water flows with a velocity of 3 m/s at a depth of 1.5 m in a trapezoidal channel with a 2m base and sides sloping at 45°. It empties into a circular pipe and flows at 2 m/s. What is the diameter if:
(a) The pipe flows full?
(b) The pipe flows half full?
(c) The water in the pipe flows at a depth of one-half the radius?