A patient receives a blood transfusion trough a needle of diameter 0.20 mm and length 2.5 cm. The density of blood is 1050 kg/m^3. The bottle supplying the blood is 0.50 m above the patient's arm. The viscosity of blood is 2,7x10 3 Ns/m'. a) What is the rate of flow trough the needle? b) How long will it take to inject 1 pint (500cm^3) of blood into the patient