A 2.0 N force is applied to the plunger of a hypodermic needle. The diameter of the plunger is 1.2 cm and that of the needle is 0.30 mm.
(a) With what force does the fluid leave the needle?
(b) What force on the plunger would be needed to push fluid into a vein where the gauge pressure is 18 mm Hg? Answer for the instant just before the fluid starts to move.