Pressure on a submarine window homework

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SUMMARY

The discussion centers on calculating the maximum safe depth for a research submarine with a 40.0 cm diameter window that is 8.30 cm thick, capable of withstanding forces up to 1.00×106 N. The relevant equation for pressure is p = P0 + ρgh, where P0 is atmospheric pressure, ρ is the density of water, g is the acceleration due to gravity, and h is the depth. Participants clarify that the pressure inside the submarine is maintained at 1.0 atm, and the pressure needed to break the window must be calculated using the relationship p = F/A, leading to the equation Total Pressure = 101.3 + (9.8 × d × 1000).

PREREQUISITES
  • Understanding of pressure equations, specifically p = P0 + ρgh
  • Knowledge of the relationship between force and area (p = F/A)
  • Familiarity with the concepts of atmospheric pressure and its role in underwater scenarios
  • Basic understanding of fluid density, particularly the density of water
NEXT STEPS
  • Research how to calculate pressure at different depths in water using the equation p = P0 + ρgh
  • Learn about the properties of materials used in submarine construction, focusing on pressure resistance
  • Explore the implications of atmospheric pressure in underwater environments and its effects on submersible design
  • Study the relationship between force, area, and pressure in engineering applications
USEFUL FOR

Students studying physics or engineering, particularly those focused on fluid mechanics and pressure calculations in underwater environments.

mz.mary00
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1. Homework Statement

A research submarine has a 40.0 -diameter window 8.30 thick. The manufacturer says the window can withstand forces up to 1.00×106 . What is the submarine's maximum safe depth?

2. Homework Equations
p=Po + pgh3. The Attempt at a Solution
p = 1.01x 10^5 + ? X9.8 x 8.3

i don't know how to find that p since we were not given mass
please helppp i am so confused of what to do
 
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Hint: Pressure on the outside = Pressure on the inside, at max depth. Pressure on the outside depends on the density of the water, air pressure and depth. Pressure on the inside at max depth equals air pressure and strength of the window.

Note that it was a long time since I did this so I'm a little unsure
 
mz.mary00 said:
2. Homework Equations
p=Po + pgh
That equation is:
Total Pressure = Atmospheric pressure + density*g*depth

What's the density of water? (You don't need the mass of anything.)

First figure out what pressure is needed to break the window. How does pressure relate to force?
 
p= F/A
 
The pressure inside the submarine is maintained at 1.0 atm
do we ignore that fact
 
Last edited:
The pressure on the inside of the window is air pressure + something else, the "something else" has to do with the window.
 
mz.mary00 said:
p= F/A
So use the given information to figure out the pressure that would break the window.
mz.mary00 said:
The pressure inside the submarine is maintained at 1.0 atm
do we ignore that fact
The question is ambiguous. "The manufacturer says the window can withstand forces up to 1.00×106 ." doesn't specify whether that is the net force or just the outside force.

I would pressume they meant the net force. (So ignore atmospheric pressure since it's canceled by the inside pressure.)
 
in other words we have to find the outer pressure or is that the atmostpheric pressure, so what happens afterwards, i am not sure is that the atmostpheric pressure?
 
then it becomes
Total pressure = 101.3+ (9.8 X d X 1000)

=101.3 + 9800d

and now my question is , how do i get my value for d?
 
Last edited:
  • #10
mz.mary00 said:
then it becomes
Total pressure = 101.3+ (9.8 X d X 1000)
What's the 101.3?

and now my question is , how do i get my value for d?
You'll solve for it. The pressure is not an unknown; you can figure it out from the information given about the window.
 

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