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If I have an ocean with constant temp 10 degrees celcius and I throw in an 8 gram iron ball that's 50 degrees celcius, I'd like to find how to calculate the amount of energy that flows into the water before equilibrium.

How would I go about doing this?

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How big is the ocean? – fizzer Mar 29 '11 at 12:10
Mark has provided you with an answer, but in my opinion this question is way too elementary for this site, so I am voting to close. Don't take this personally. If your question has some hidden nontrivial content, please update it and I'll remove my vote. – Marek Mar 29 '11 at 12:15
Oh I see, I wasn't aware that there was a lower bound on difficulty for this site. I just started learning thermal physics, unfortunately. You're probably right though.. – Navin Aggrawal Mar 29 '11 at 12:29
sorry but there is a definite policy not to make this a homework answers site. ps. Assume the ocean doesn't change temperature so this is just the amount of energy in a ball of iron heated by 40deg (Q = mcT) – Martin Beckett Mar 29 '11 at 15:24
up vote 4 down vote accepted

In order to lower the temperature of the iron, it will have to transfer heat to the water.

The heat transferred per degree of cooling (per gram) is called the heat capacity of the iron. This number is about 0.45 J/(gK) (same link). In general, the heat capacity can depend on the temperature, but for many solids it is pretty much constant.

To find the total heat transferred, multiply the mass, heat capacity, and temperature change.

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