Energy and specific heat (berkley review-am i crazy?)

[manohman]

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Really stumped by this question. It should be simple math right
7.6*10^13 / (4200*100) = 1.44*10^8

But thats not even one of the answers

 

[rabbott1971]

I'm not the best at these, but this seems like a q=mc(deltaT) problem.
Although you have a conversion issue of Kelvin to Celsius, I don't think it matters because it still gives you a deltaT of 100. So I would solve it pretty much like you did:

m=q/c(deltaT)
m=7.6*10^13/4.2*10^3(10^2)=1.8*10^8.

I would have picked D although it is off by a power of 10. Answer A is also off by a power of 10 from what the solution would be if you applied the efficiency rating to the nuclear energy output (which the question stem says NOT to do). Weird! Maybe someone smarter will come along and point out why it is not a mistake.

Do you have the solution from the materials?

 

[manohman]

I'm not the best at these, but this seems like a q=mc(deltaT) problem.
Although you have a conversion issue of Kelvin to Celsius, I don't think it matters because it still gives you a deltaT of 100. So I would solve it pretty much like you did:

m=q/c(deltaT)
m=7.6*10^13/4.2*10^3(10^2)=1.8*10^8.

I would have picked D although it is off by a power of 10. Answer A is also off by a power of 10 from what the solution would be if you applied the efficiency rating to the nuclear energy output (which the question stem says NOT to do). Weird! Maybe someone smarter will come along and point out why it is not a mistake.

Do you have the solution from the materials?

yeah they said it was D which i came up with as being off by a factor of 10 as well!

im literally confounded lol

 

[aldol16]

First of all, 7.6/4.2 = 1.8, not 1.44. So the correct answer will have 1.8 in it. As to the powers, you are correct and they are off by a factor of 10. 10^13/(10^3*10^2) = 10^8.