Please explain this entropy change formula for me?

AI Thread Summary
The discussion revolves around calculating the entropy change of a lake when a 2.00 kg aluminum bar at 300°C is submerged in it, with the lake's temperature at 15.0°C. The specific heat capacity of aluminum is given as 900 J/(kg*K). The problem assumes that the lake's temperature remains constant due to its large size. The user initially seeks clarification on the entropy change formula but later indicates they have resolved the issue independently. The focus is on understanding the entropy change in thermal equilibrium scenarios.
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[SOLVED] please explain this entropy change formula for me??

An aluminum bar of mass 2.00 kg at 300 Celsius is thrown into a lake. The temperature of the water in the lake is 15.0Celsius; the specific heat capacity of aluminum is 900 J/(kg*K).
The bar eventually reaches thermal equilibrium with the lake. What is the entropy change DeltaS_lake of the lake? Assume that the lake is so large that its temperature remains virtually constant.
 
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nvm i got it
 
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