Question

Calvin is drinking milk through a straw. The straw has a diameter of 4 mm, which is much narrower than the cup itself. The straw has a length L = 18 cm, and the level of milk in the cup is H = 11 cm. At this instant, the absolute pressure in Calvin’s mouth is only 95.9 percent of atmospheric pressure. Milk has the same density as water. With what speed does the milk travel through the straw? What is the mass flow rate through the straw? If you could show all the steps to get the answer that would be a huge help! Thank you!

Answer 1

Using the Bernoulli's equation

101325+ 0.5*1000*0² + 1000*9.8*0.11 = 0.959*101325 + 0.5*1000*v² + 1000*9.8*0.18

v = 2.63 m/s

Flow rate =

Taking density as 1000kg/m³

mass flow rate = 3.305*10^-5*1000 = 3.305*10^-2 Kg/s