A round pipe of varying diameter carries petroleum from a wellhead to a refinery. At the wellhead the pipe\'s diameter is 52.3 cm (0.523 m) and the flow speed of the petroleum is 12.3 m/s. At the refinery the petroleum flows at 5.41 m/s. What is the volume flow rate of the petroleum along the pipe and what is the pipe\'s diameter at the refinery?