== 4. An oil with a viscosity of μ = 0.40 N-s / m² and density p = 900 kg/m³ flows in a horizontal pipe of diameter D = 0.20 m and length, L= 10m. The basic physics behind laminar fluid flow says that the flowrate Q, varies directly as the pressure drop, Ap and the radius, r, raised to the 4th power and inversely as the viscosity μ, and length of pipe L. The proportionality constant is π/8. a) Write this as an equation. b) Determine the required pressure drop, Ap in N/m² to produce a flowrate of Q=2.0 x 10-5 m³/s. 5. You completed your degree and just took a position earning $60,000 per year. You are determined to maintain your salary at a rate higher than the expected 3% inflation per year. What must your salary be 5 years from now to just maintain your standard of living?