Question a/b pressure variation equation

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    Pressure Variation
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The discussion revolves around understanding the pressure variation equation as applied to two problems: the height water can be sucked up a straw and the maximum depth organisms can survive underwater. The professor's solution for the straw problem indicates that a pressure reduction of 10 kPa allows water to be lifted approximately 1.0 meter. The participant's attempt at the solution is questioned, particularly regarding the correct application of atmospheric pressure in calculations. In the second problem, the professor explains that the maximum pressure for organisms is 1000 atm, leading to a depth of about 10 km, prompting confusion about the relationship between total pressure and atmospheric pressure. The participant seeks clarification on the pressure difference in their lung scenario, specifically questioning the calculation of 1 atm - 10 kPa.
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Hi everyone, i have a question abuot how my professor is using the pressure variation equation and I would really appreciate help with it!

Homework Statement



How high can you suck water up a strw? The pressure in the lungs can be reduced to about 10 kPa below atmospheric pressure

2. Professor's Solution

P=Patm+ρgd --> d=(P-Patm)/ρg --> d=(10 kPa)/(1000 kg/m^3 * 9.8 m/s^2) = 1.0 m

3. My attempt at the problem

P=Patm+ρgd --> d=(P-Patm)/ρg --> d=(101.3 kPa-(1atm-10 kPa)/(1000 kg/m^3] * 9.8 m/s^2) =

What is wrong with my attempt at the solution.

Another example of my professor's solution is in this problem:

Homework Statement



The maximum pressure most organisms can survive is abotu 1000 times atmospheric pressure. ONly small, simple organisms such as tadpoles and bacteria can survive such high pressure. What then is the maximum depth at whic these organisms can live under the sea (assuming that the density of seawater is 1025 kg/m^3?

2. Professors Solution

P=Patm+ρgd --> d=(P-Patm[/SUB)/ρg --> d=(1000 atm)/(1025 kg/m3 * 9.8 m/s2) * (1.013e5 Pa/atm) = 10 km

Why does 1000 atm= P-Patm[/SUB) ? wouldn't P-Patm[/SUB) be (1000*1 atm)-(1atm)?


I would really appreciate some help with this problem! Thank you!
 
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If the pressure in your lungs can be reduced 10 kPa below atmospheric, what is the difference in pressure between the atmosphere and the inside of your lungs?
 
Thank you very mcuh for your reply

1 atm - 10 kPa?
 
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