# Thread: How do I figure this out?

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## How do I figure this out?

A cylinder with 1,500 sq. in. of internal surface contains R-22 and is in a service truck body at 120°F. What is the total outward force of the refrigerant against the inner wall of the cylinder in tons of pressure?

A. 202.64
B. 226.61
C. 194.92
D. 145.71

Can someone give me the equation to figuring this one out?

2. It's C

R-22@120*=260 PSI (pounds per square inch)
you have 1500 sq in, so

260 x 1500 = 390000 pounds
1 ton=2000 pounds

390000/2000= 195

3. Regular Guest
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Thanks Nightranger!!

4. No prob

5. That question was really tricky, though and I'd love to know the real-world practical application for that. Or is it just meant to scare you from getting your tanks too hot?

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nice thinking nightranger but R-22 @120* is 260 PSIG which is equivalent to 274.696 PSI (pounds per square inch)

7. Thats 260PSIG, or 274.696 PSIA.
Since A would be low if using PSIA, I think C is the answer they were looking for.

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ya just sayin he forgot to say it was PSIG and not PSI because if he writes that on some homework he may loose some marks if the PROF is in a bad mood, witnessed it happen to often

9. Originally Posted by Matt-
ya just sayin he forgot to say it was PSIG and not PSI because if he writes that on some homework he may loose some marks if the PROF is in a bad mood, witnessed it happen to often
True. But you didn't explain that in your first post.

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