Struggling with a Homework Problem - Need Assistance

AI Thread Summary
The discussion revolves around determining the maximum height of a vertical soda straw that can be used to drink. The key point is that the pressure at the bottom of the straw must be less than atmospheric pressure for the liquid to rise, which is influenced by the depth of the water. It is noted that to achieve a greater height of water in the straw, one would need to increase the ambient pressure above 1 atm. The initial confusion regarding the relationship between depth and length is clarified, emphasizing the importance of pressure in this scenario. Understanding these principles is essential for solving the homework problem effectively.
Gott_ist_tot
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I received a homework problem that I need guidance on where to start.

What is the longest vertical soda straw you could possibly drink from?

I do not know where to start on this problem. A small push in the right direction would be greatly appreciated.
 
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As I posted this I had a possible epiphany.

p = /rhogd

If the depth at which the straw is submerged makes rho*g*d greater than 101.3 kPa than the water above the end of the straw keeps the water down. Although now I know that won't work because that is how deep the straw is not how long it is.
 
Gott_ist_tot said:
As I posted this I had a possible epiphany.

p = /rhogd

If the depth at which the straw is submerged makes rho*g*d greater than 101.3 kPa than the water above the end of the straw keeps the water down. Although now I know that won't work because that is how deep the straw is not how long it is.
in TeX, write /rho as \rho to get the correct letter.

Your approach is correct. One must identify the height (depth) of water, which gives a pressure drop of 1 atm, since it is assumed that the reservoir of water is at one atmosphere (101325 Pa) absolute, and the lowest pressure one could achieve is a pure vacuum of ~ 0 Pa.

The only way to obtain a greater head of water is to increase the ambient pressure above 1 atm.
 
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