There are two reservoirs- one containing blood, another containing plasma. Reservoir 1, containing blood, is at a higher level than Reservoir 2 containing plasma. They are connected with a clamped tube at the bottom of the reservoirs. The initial temperatures of the two fluids are different. Neglect the difference in density between blood and plasma and assume the pressure at the bottom of each reservoir is equal to the hydrostatic pressure rho*gh. Show that after the clamp is released the flow rate decreases exponentially with time. How to set up the problem to prove that the flow rate decreases exponentially with time?