Pressure in a Lake: Find Depth for 4.5 atm

[Manda_24]

Homework Statement

At the surface of a freshwater lake the air pressure is 1 atm. At what depth under water in the lake is the water pressure 4.5 atm?

Homework Equations

P=a+hgp
h=(P-a)/(g*p)

The Attempt at a Solution

h=(4.5x10⁵ - 1x10⁵)/(9.8*1000)=35.71
I also did the equation with 9,000 Pa converted to atm, which I think it what I'm supposed to do but I still get the incorrect answer.

 

[Gear300]

Convert everything to pascals before using the equations. Also, be sure that the density you have for freshwater is in kg/m³. I'm not seeing anything wrong in your method, so I'm assuming the problem is in the units.

 

[JDHalfrack]

"h=(4.5x105 - 1x105)/(9.8*1000)=35.71" Appears to be correct. If I am not mistaken, 10 m of water is roughly = to 1 atm. But, I am not 100% sure off the top of my head. If that's the case, it would make sense that 35 m of water would be about 3.5 atm plus the 1 atm from the atmosphere = 4.5 atm.

If you know, what is the answer supposed to be?

 

[Manda_24]

Convert everything to pascals before using the equations. Also, be sure that the density you have for freshwater is in kg/m³. I'm not seeing anything wrong in your method, so I'm assuming the problem is in the units.

Thanks, I just needed to convert the top to pascals, I thought I only had to do it to the bottom.