The plunger of a syringe has an internal diameter of 1.0 cm and the end of the needle has an internal diameter of 0.30 mm. A practitioner squeezes across the plunger very lightly, but no serum is emitted by the needle into a vein. So the practitioner gradually increases the force that she exerts across the plunger and eventually serum begins to be emitted from the needle into the vein. Assuming no friction, what is the minimum net force that the practitioner applies across the plunger in order that serum begins to be emitted from the needle into the vein? Take the pressure of blood in the vein to be 20 mmHg above that of atmospheric pressure. 3.3N 1.2N 0.21 N 0.70 N 1.4 N 23 N
Viscosity
The measure of the resistance of a fluid to flow is known as viscosity. Most fluids have some resistance to motion, the resistance provided by the fluid is called viscosity. This resistance is created by the force of attraction between the fluid molecules. If you pour water through a funnel, it flows easily and quickly, because it has very little resistance. But if you pour honey through a funnel, it may take a little time longer, as the density of honey is high.
Poiseuille's Law
The law of Poiseuille or Poiseuille's equation states that the pressure drop of an incompressible fluid especially a liquid in a laminar flow that passes through a cylindrical tube of length L, radius r, pressure gradient ΔP, and mainly depends on the viscosity of the fluid is nothing but the pressure difference of the layers of fluids. ΔP=P1-P2
Drag Forces
Forces that occur due to the movement of fluid are known as fluid mechanics. Following are the fluids present:
Step by step
Solved in 2 steps
