Calculating Pressure Difference in Blood Flow Using Bernoulli's Equation

In summary, an artery of radius 1 mm leaves the heart and travels upward 0.3 m to your shoulder, where it breaks into 3 smaller veins, each of radius 0.5 mm. Blood flows through the artery at a speed of 0.8 m/s as it leaves the heart. The density of blood is 1050 kg/m^3. The blood moves at 1.07 m/s in the smaller veins. Using Bernoulli's equation, the difference in pressure between a point in the artery and a point in one of the smaller veins is determined to be 3341 pascals. However, this method may not be accurate due to the viscosity of blood and the small radii of
  • #1
GemmaN
2
0
"An artery of radius 1 mm leaves the heart and travels upward 0.3 m to your shoulder, where it breaks into 3 smaller veins, each of radius 0.5 mm. Blood flows through the artery at a speed of 0.8 m/s as it leaves the heart. The density of blood is 1050 kg/m^3."
I determined that the blood moves at 1.07 m/s in the smaller veins, which is correct.

I am suppose to find the difference in pressure "between a point in the artery just as it leaves the heart and a point in one of the smaller veins just at the point where they split off"
I am pretty sure I am suppose to use bernoulli's Eqn.

P1 + d*g*y1 + 1/2 *d*v1^2 = P2 + d*g*y2 + 1/2 *d*v2^2
P1 + (1050 kg/m^3)(9.8 m/s^2)(0.3m) + (1/2)(1050kg/m^3)(0.8m/s)^2 = P2 + 0 + (1/2)(1050kg/m^3)(1.07m/s)^2

I have everything to use this equation, but the initial pressure. Am I missing a way to figure that out? I can't seem to get any of my pressure equations to work for this, P = F/A, P = P0 + dgh

The answer is suppose to be 3341 pascals
 
Physics news on Phys.org
  • #2
The initial pressure is not needed. The difference in pressure is equal to (P2-P1), usually abbreviated as [tex]\Delta P[/tex].
 
  • #3
What CRAZY individual thinks up an exercise where Bernoulli's equation is to be used on blood flow?

Blood is an extremely viscous fluid, and the arteries with so small radii, that any information gained from using Bernoulli's equation is guaranteed to be dead wrong.

At the very least, Hagen-Pousseille flow should be used as a base modelling tool (that's probably inaccurate as well).
 

1. What is pressure?

Pressure is the amount of force applied per unit area. It is typically measured in units of Pascals (Pa) or pounds per square inch (psi). In physics, pressure is often represented by the symbol "P".

2. How is pressure related to Bernoulli's equation?

Bernoulli's equation states that the total energy of a fluid in a closed system remains constant. This means that as the speed of a fluid increases, its pressure decreases. This relationship is known as the Bernoulli principle.

3. What is the significance of Bernoulli's equation?

Bernoulli's equation is significant because it helps us understand the behavior of fluids in motion. It is commonly used in the study of aerodynamics and fluid mechanics, and has practical applications in fields such as aviation and engineering.

4. How is Bernoulli's equation applied in real-life situations?

Bernoulli's equation can be applied in a variety of real-life situations, such as the lift force on an airplane wing, the flow of water through pipes, and the operation of a carburetor in a car engine. It is also used in the design of airfoils, turbines, and other devices that rely on fluid dynamics.

5. Are there any limitations to Bernoulli's equation?

While Bernoulli's equation is a useful tool for understanding fluid behavior, it does have some limitations. It assumes that the fluid is incompressible, non-viscous, and has a steady flow. In reality, these conditions may not always be met, so the equation may not accurately predict the behavior of fluids in certain situations.

Similar threads

  • Introductory Physics Homework Help
Replies
30
Views
1K
  • Introductory Physics Homework Help
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
747
  • Introductory Physics Homework Help
Replies
2
Views
835
  • Introductory Physics Homework Help
Replies
15
Views
438
  • Introductory Physics Homework Help
Replies
6
Views
4K
  • Introductory Physics Homework Help
Replies
1
Views
3K
  • Introductory Physics Homework Help
Replies
16
Views
1K
Back
Top