Find pressure at depth of freshwater

  • Thread starter Thread starter cc2hende
  • Start date Start date
  • Tags Tags
    Depth Pressure
Click For Summary

Homework Help Overview

The problem involves calculating the pressure experienced at a depth of 100 meters while scuba diving in freshwater. The context includes the density of freshwater and the atmospheric pressure at the surface.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the application of the pressure formula P2 = P1 + pgd and express confusion regarding the units of the calculated pressure. There are attempts to clarify the conversion of pressure from N/m² to atm and the consistency of units in the equation.

Discussion Status

Some participants have provided guidance on ensuring unit consistency and converting the final pressure to the desired units. Multiple interpretations of the pressure calculation and unit conversion are being explored, but no consensus has been reached.

Contextual Notes

There is an emphasis on the need for consistent units in the calculations, and participants are questioning the appropriate use of gravitational acceleration in terms of units.

cc2hende
Messages
7
Reaction score
0

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.
 
Physics news on Phys.org
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
 
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
 
cc2hende said:

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.
 

Similar threads

Replies
2
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
2
Views
4K
Replies
1
Views
3K
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K