Question
Velocity should be in m/s.
A hypodermic syringe contains a medicine with the density of water (see figure below). The barrel of the syringe has a cross-sectional area A = 2.80 times 10-5 m2, and the needle has a cross-sectional area a = 1.00 times 10-8 m2. In the absence of a force on the plunger, the pressure everywhere is 1.00 atm. A force Frightarrow of magnitude 3.10 N acts on the plunger, making medicine squirt horizontally from the needle. Determine the speed of the medicine as it leaves the needle's tip.
Explanation / Answer
As we know that
P + pgh + 0.5*p*v^2 = Constant
Therefore
F/A =
(3.10/(2.80*10^-5)) = 0.5*1000*v^2
Therefore
v = 14.88 m/sec