The hypodermic needle in Fig. P3.23 contains a liquid serum (SG = 1.05). D1=0.75 in, D2=0.030 in. If the serum is to be injected steadily at 6 cm3/s, how fast in in/s should the plunger be advanced (a) if leakage in the plunger clearance is neglected and (b) if leakage is 10 percent of the needle flow?