Air Pressure Conversion: Units to Meters

In summary, the given equation is dp/dh = -0.13*p, where p represents air pressure in kg/cm^2 and h represents height in km. To convert the units for the constant 0.13 from km to m, we need to multiply it by 0.00013 meters^-1.
  • #1
Poetria
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Homework Statement


[/B]
dp/dh = -.13*p h in kilometers

I should convert it into meters2. The attempt at a solution

I thought it would be enough to multiply -0.13 by 1000. :(

dp/dh = -130*p but it is wrong.

 
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  • #2
The statement of the problem is not clear. What are you trying to do, what does the formula that you posted represent and what are the units for this number 0.13?
 
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  • #3
dp/dh=-0.13*p
dp/dx = ??

p - air pressure in kg/cm^2

h - height in km
I should convert h in km into x in meters.

What is the differential equation for p if altitude is measured in meters x instead of kilometers h?
 
  • #4
Poetria said:
dp/dh=-0.13*p
dp/dx = ??

p - air pressure in kg/cm^2

h - height in km
I should convert h in km into x in meters.

What is the differential equation for p if altitude is measured in meters x instead of kilometers h?
From the equation given, you can deduce that the constant 0.13 has dimension L-1. Since we are told the distance unit is km, we can say it is 0.13km-1.
To convert to m, we need to multiply km-1 by unity in the form of a constant with units km/m. What would that be?
 
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  • #5
haruspex said:
From the equation given, you can deduce that the constant 0.13 has dimension L-1. Since we are told the distance unit is km, we can say it is 0.13km-1.
To convert to m, we need to multiply km-1 by unity in the form of a constant with units km/m. What would that be?

Oh dear, I understand what's wrong.

0.00013 meters
 
  • #6
Poetria said:
Oh dear, I understand what's wrong.

0.00013 meters
Right number, wrong dimension.
 
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  • #7
Of course:

0.00013 meters^-1

Thank you very much. :)
 
  • #8
Poetria said:
Of course:

0.00013 meters^-1

Thank you very much. :)
Right.
 
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Related to Air Pressure Conversion: Units to Meters

1. What is air pressure?

Air pressure is the force exerted by the weight of air in the atmosphere. It is measured in units of force per unit area, such as pounds per square inch (psi) or pascals (Pa).

2. How is air pressure converted from units to meters?

Air pressure can be converted from units to meters using the formula: P = ρgh, where P is the pressure in pascals, ρ is the density of air in kg/m^3, g is the acceleration due to gravity (9.8 m/s^2), and h is the height in meters. This formula is based on the relationship between pressure, density, and height in a column of air.

3. What are some common units used to measure air pressure?

Some common units used to measure air pressure include pascals (Pa), pounds per square inch (psi), atmospheres (atm), and millibars (mb). Different fields of study and industries may use different units, so it is important to always specify the units when discussing air pressure.

4. Why is it important to convert air pressure to meters?

Converting air pressure to meters is important because it allows for a better understanding of the relationship between pressure and height in the atmosphere. It also allows for easier comparison between different units of air pressure and can aid in calculations and analysis in various scientific and engineering applications.

5. Can air pressure be negative?

Yes, air pressure can be negative, meaning it has a value less than atmospheric pressure at sea level. Negative air pressure can occur in situations such as low-pressure systems or at high altitudes. It is important to take into account the sign of air pressure when converting units to meters.

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