Find pressure at depth of freshwater

[cc2hende]

Homework Statement

You are scuba diving to reach a ship sunk at a depth of 100m. What is the pressure in atm at this depth? Density of fresh water is 1000kg/m^3 and air pressure at lake surface=1atm=1.013x10^5 N/m^2

Homework Equations

P2=P1+pgd
p=density

The Attempt at a Solution

P2=P1+pgd
P2=(1.013x10^5 N/m^2) + (1000kg/m^3)(9.8m/s^2)(100m)
P2=1081300
Its at this point that i get confused. I don't know what the units are for this answer.

 

[technician]

You have the correct answer for the pressure in N/m^2
If you are asked for the pressure in atmospheres then you must divide by atmospheric pressure in N/m^2

 

[Roestreyev]

instead of 9.8 m/s^2 you should use 9.8 N/kg to get correct units

(kg/m^3)(N/kg)(m) will give you N/m^2

 

[Chestermiller]

Homework Statement

You are scuba diving to reach a ship sunk at a depth of 100m. What is the pressure in atm at this depth? Density of fresh water is 1000kg/m^3 and air pressure at lake surface=1atm=1.013x10^5 N/m^2

Homework Equations

P2=P1+pgd
p=density

The Attempt at a Solution

P2=P1+pgd
P2=(1.013x10^5 N/m^2) + (1000kg/m^3)(9.8m/s^2)(100m)
P2=1081300
Its at this point that i get confused. I don't know what the units are for this answer.

Both terms in the equation have to have the same units. That is, the units of the two terms must be consistent. You already know the units of the first term. Just make sure that the units of the second term are consistent. It, of course, helps to know that Newtons are the same kg-m/sec².

 

[Nickie]

The answer you have calculated is in pascals (Pa), which is the SI unit for pressure. To convert to atmospheres (atm), you can divide by the standard atmospheric pressure of 1.013x10^5 N/m^2, which gives a final pressure of approximately 10.66 atm. This means that at a depth of 100m, the pressure is equivalent to 10.66 times the atmospheric pressure at the surface.