4. (Text book problem 4.14, 2nd Edition) A drug is being injected at a constant infusion rate of Q from a syringe of diameter D into a needle of diameter d (Figure). The fluid viscosity is μ and density is p. Determine the force on the syringe. Assume that the flow through the catheter is laminar and that the blood pressure is P. State all other assumptions are made. Diameter D needle diameter d 2 P

Fig: 1