A conveyor belt moves to the right with a speed v = 300 m/min. A very fast piemaker puts pies on the belt at a rate of 20 per minute, and they are received at the other end by a pie eater.

(a) If the piemaker is stationary, find the spacing l between the pies and the frequency f with which they are received by the stationary pie eater.

(b) The piemaker now walks with a speed of 30 m/min toward the receiver while continuing to put pies on the belt at 20 per minute. Find the spacing of the pies and the frequency with which they are received by the stationary pie eater.

(c) Repeat your calculations for a stationary piemaker and a pie eater who moves toward the piemaker at 30 m/min.