# Simple Question for my homework

1. Jul 29, 2008

### noobies

could u guys please help me, i need to determine the pressure difference between the two pipelines, and i know how to calculate those problem, but the problem is should i just ignored the air column in my analysis to find the difference pressure??

2. Jul 29, 2008

### noobies

please let me know if possibly the way that im asking for help doesnt suit with any of this forum term okay, im still new here thanks mate

3. Jul 29, 2008

### Staff: Mentor

I'll move your thread to Intro Physics to get it more views.

I would think you would need to use the Ideal Gas Law for the air portion, and it seems like the pressure would be uniform throughout the air portion....

4. Jul 29, 2008

### mgb_phys

What are you actually trying to find - whats the question?

5. Jul 29, 2008

### noobies

i need to find the difference of the pressure between those two pipelines, i just need to know if i need to consider the air columned too??or should be ignored??once i know it, i can proceed with the calculation by my self (perhaps)

regards
noobies

6. Jul 29, 2008

### noobies

thanks mate

7. Jul 29, 2008

### mgb_phys

I see, the circles are pipes running out of the page - they looked like sealed bulbs forming a thermometer!
The pressure at each end of the air column must be the same. The air will compress - but that doesn't change things. It's exactly equivalent to just having the two water columns with a moveable piston between them.

8. Jul 29, 2008

### noobies

is actually U turn manometer, ya know that the pressure at each end must be d same..so should i ignored the air columned? to finde the diff between each end?