- #1
sonpat
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THE PROBLEM:
A steam engine's boiler completely converts 2638 g of water at 83.7 °C to steam at 195.4 °C. The steam, at a constant pressure of 3.28 Pa, expands by pushing a piston of radius 9.4 cm a distance of 8.3 cm. What is the change in internal energy of the water-steam system? MY WORK:
First I know Change In Internal Energy = Heat - Work
So I found heat using MC Delta T and Heat of Vaporization. I got 6665124.107 J.
Then I found work.
Change in Volume = Area * Distance
So in this case it's Pi R2 D or (.094m2)(pi)(.083m) which is .002304m3
Then Work = Change in Volume * Pressure
3.8 pascals* .002304m3 = .008755 J
Change in internal energy = 6665124.107 J - .008755 J = 6665124.098J
BUT THAT'S WRONG AND I DON'T KNOW WHAT I AM DOING
A steam engine's boiler completely converts 2638 g of water at 83.7 °C to steam at 195.4 °C. The steam, at a constant pressure of 3.28 Pa, expands by pushing a piston of radius 9.4 cm a distance of 8.3 cm. What is the change in internal energy of the water-steam system? MY WORK:
First I know Change In Internal Energy = Heat - Work
So I found heat using MC Delta T and Heat of Vaporization. I got 6665124.107 J.
Then I found work.
Change in Volume = Area * Distance
So in this case it's Pi R2 D or (.094m2)(pi)(.083m) which is .002304m3
Then Work = Change in Volume * Pressure
3.8 pascals* .002304m3 = .008755 J
Change in internal energy = 6665124.107 J - .008755 J = 6665124.098J
BUT THAT'S WRONG AND I DON'T KNOW WHAT I AM DOING