A horizontal pipe of diameter 1 m has a smooth constriction to a section of diameter 0.6 m. The density of oil flowing in the pipe is 821 kg/m³. If the pressure in the pipe is 7200 N/m² and in the constricted section is 5400 N/m², what is the rate at which oil is flowing? Answer in units of m³/s.
a) 0.018 m³/s
b) 0.032 m³/s
c) 0.052 m³/s
d) 0.074 m³/s