A round pipe of varying diameter carries petroleum from a wellhead to a refinery. At the wellhead the pipe's diameter is 56.1 cm and the flow speed of the petroleum is 13.1 m/s. At the refinery the petroleum flows at 6.09 m/s. What is the volume flow rate of the petroleum along the pipe and what is the pipe's diameter at the refinery?
Volume flow rate: ________m^3/s
Diameter: _______________cm