A round pipe of varying diameter carries petroleum from a wellhead to a refinery. At the wellhead the pipe\'s diameter is 50.5 cm (0.505 m) and the flow speed of the petroleum is 10.5 m/s. At the refinery the petroleum flows at 5.75 m/s. What is the volume flow rate of the petroleum along the pipe and what is the pipe\'s diameter at the refinery?