Question

A patient is to be injected with 0.4 L of an electrolyte solution in 1/2 an hour. Assuming that the solution is elevated by 1 m above the arm, and that the hydrostatic pressure alone is used to push the solution into the arm (as is typical of an IV), and assuming that the needle itself is 2.5 cm long, what inner diameter must the needle have to allow this?

(use ?η=1×10−31×10−3 Ns/m22 and ?ρ=1000 kg/m33; the values for water. Also assume that the pressure in the patient's vein is atmospheric pressure.)

Diameter =  mm

Answer 1