# Solving Fluid Dynamics Pressure at Different Speeds

• narutoish
In summary, the question asks for the pressure reading at a speed of 700 km/h if the reading at 150 km/h is 17.0 mm Hg. The equation p = p2+ 1/2 density (v2^2 - v1^2) can be used, but the density is unknown. The tip of the pitot tube measures the stagnation pressure and if the density remains constant, the stagnation pressure is directly proportional to the approach velocity.
narutoish

## Homework Statement

If the pressure reading of your Pitot tube is 17.0 mm Hg at a speed of 150 km/h, what will it be at 700 km/h at the same altitude?

## Homework Equations

The only eq I could think if is p = p2+ 1/2 density (v2^2 - v1^2)

But I don't know the density

## The Attempt at a Solution

So I pretty much get stuck in the beginning, any help will be nice

Thanks

What would the reading be at 0km/h? What equations do you now have?
(Note: I'm assuming the equation you quoted is appropriate. To check that I'd need to do some research.)

narutoish said:

## Homework Statement

If the pressure reading of your Pitot tube is 17.0 mm Hg at a speed of 150 km/h, what will it be at 700 km/h at the same altitude?

## Homework Equations

The only eq I could think if is p = p2+ 1/2 density (v2^2 - v1^2)

But I don't know the density

## The Attempt at a Solution

So I pretty much get stuck in the beginning, any help will be nice

Thanks

At the tip of the pitot tube, the velocity is zero. So you are measuring the stagnation pressure. If the density doesn't change between the two cases, how does the stagnation pressure depend on the approach velocity?

Chet

## 1. What is fluid dynamics pressure?

Fluid dynamics pressure is the force per unit area exerted by a fluid on its surroundings. It is caused by the random motion of the fluid's molecules and increases with the density and velocity of the fluid.

## 2. How does fluid pressure change at different speeds?

As the speed of a fluid increases, its pressure decreases. This is due to Bernoulli's principle, which states that as the speed of a fluid increases, its pressure decreases because the energy of the fluid is distributed over a larger area.

## 3. What factors affect fluid pressure at different speeds?

The main factors that affect fluid pressure at different speeds are the density and velocity of the fluid. Other factors that can impact fluid pressure include temperature, viscosity, and the shape of the object the fluid is flowing over.

## 4. How is fluid pressure measured?

Fluid pressure can be measured using instruments such as manometers, pressure gauges, and pressure transducers. These instruments use different techniques to measure the force exerted by the fluid on a specific area.

## 5. How can fluid pressure at different speeds be calculated?

Fluid pressure at different speeds can be calculated using Bernoulli's equation, which takes into account the density, velocity, and height of the fluid. This equation can be used to calculate the pressure at different points along the fluid's flow path.

• Introductory Physics Homework Help
Replies
13
Views
346
• Introductory Physics Homework Help
Replies
6
Views
2K
• Introductory Physics Homework Help
Replies
1
Views
893
• Classical Physics
Replies
8
Views
383
• Introductory Physics Homework Help
Replies
7
Views
2K
• Introductory Physics Homework Help
Replies
10
Views
3K
• Introductory Physics Homework Help
Replies
1
Views
1K
• Introductory Physics Homework Help
Replies
24
Views
2K
• Introductory Physics Homework Help
Replies
1
Views
2K
• Introductory Physics Homework Help
Replies
1
Views
2K