Question on finding absolute pressure?

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    Absolute Pressure
delfinofrank
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Hey, here's the question:

"If a gauge reads -295mmHg where athmospheric pressure is 101.7 kn/m^2 and the vapor pressure is 2.8 kN/m^2, what is the absolute pressure?"

I converted the gauge pressure to 39.36 kN/m^2 but where do i go from here? I know the equation is p_gauge= p_absolute - atmospheric, but where do I factor in the vapor pressure?!

Please help! Thank you :)
 
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delfinofrank said:
I converted the gauge pressure to 39.36 kN/m^2 but where do i go from here? I know the equation is p_gauge= p_absolute - atmospheric, but where do I factor in the vapor pressure?!
I think your equation is correct. I'm reasonably sure that the vapor
pressure is not a factor here. It seems that was included just to throw you off track.
 
To solve this, I first used the units to work out that a= m* a/m, i.e. t=z/λ. This would allow you to determine the time duration within an interval section by section and then add this to the previous ones to obtain the age of the respective layer. However, this would require a constant thickness per year for each interval. However, since this is most likely not the case, my next consideration was that the age must be the integral of a 1/λ(z) function, which I cannot model.
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