# Atmospheric pressure homework

1. Apr 25, 2006

### zenmasterwombles

Im glad this website is here for help, cause physics is nuts, but i enjoy it.

question is at 11km below sea level what is the pressure in atmosphere.

now ive got the equation p=(h)(g)(d)

ive got g=9.8 m/s d=1030kg/m3 (given to us) but the height is what is throwing me off, in my notes i have that it needs to be converted, but to what columns? i have that written down but cant find anywhere if columns is what it needs to be in or what, if someone can tell me what to convert the columns into that would be very helpful, thank you

2. Apr 25, 2006

### Andrew Mason

Think of it as the weight of the air on a 1 m^2 area. The pressure at 11 km below sea level is the pressure at sea level plus the weight of this 1 m^2 x 11km column of air.

AM

P.S. Better check your figure for density of air. You are about 3 decimal places out.

Last edited: Apr 25, 2006
3. Apr 26, 2006

### mukundpa

Find the pressure at the depth and then divide it by atmospheric pressure. A pressure of 2 atm. means the pressure is twice as that of atmospheric pressure.

(Check whether the density of water is to be taken constant!)

MP

4. Apr 26, 2006

### Andrew Mason

I misunderstood the question. I thought it was asking what the atmospheric pressure would be at a depth of 11 km. It is asking what the water pressure would be at a depth of 11km in the ocean.

Use the same approach I suggested, but use your 1030 kg/m^3 for the density of sea water. What is the weight of an 11km column of water having an area of 1 m^3? That the the additional pressure.

AM

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