Question

A hypodermic syringe contains a medicine with the density of water (figure below). The barrel of the syringe has a cross-sectional area of 2.71 x 10-5 m2. In the absence of a force on the plunger, the pressure everywhere is 1.00 atm. A force F of magnitude 1.90 N is exerted on the plunger, making medicine squirt from the needle. Determine the medicine's flow speed through the needle. Assume the pressure in the needle remains equal to 1.00 atm and that the syringe is horizontal. 16.35 Your response differs from the correct answer by more than 10%. Double check your calculations. m/s

Answer 1

Solho grüen data p= 1000 kg/m² A = 2.71x106m2 Po = 1.00amm f = 1.90N le ng pressure introduced by the appljed forcee on the plunger = E= 1.90 - 70110.70 N/m² A 2.71x105 Since the pressure inside and out side othe Syringe are equal then AP = Po-Potp =1.00 atm 1.0ootm+(70110.70NAM3) = 101325-10115770110.70) =P AP = 7011070N/m2 AP = 40110.70N /7727 Apply benullus egh AP = 1/2 pv2 V2 20p 12x 70110.70 VJ22 - 2* 70110.70 1000 JV = 11.8 ms