Pressure on a submarine window homework

AI Thread Summary
The discussion revolves around calculating the maximum safe depth for a submarine window based on its specifications. The window has a diameter of 40.0 cm and a thickness of 8.30 cm, with a maximum force tolerance of 1.00×10^6 N. Participants emphasize using the pressure equation p = Po + pgh, where the pressure needed to break the window must be determined. Clarifications are made regarding the atmospheric pressure inside the submarine and how it relates to the external pressure at depth. Ultimately, the solution involves calculating the depth (d) using the known pressure values and the window's force capacity.
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
 
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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?
 
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  • #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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