A milkshake has a viscosity of 0.50 Pa • s. To drink this shake through a straw of diameter 0.56 cm and length 22 cm, you need to reduce the pressure at the top of the straw to less than atmospheric pressure. If you want to drain a 480 mL shake in 2.0 minutes, what pressure difference is needed? You can ignore the height difference between the top and the bottom of the straw.