# What is the entropy change of the meteor

1. Jul 28, 2008

### kitkat2950

A 3400kg meteor (c=450 J/KgC) at 1250 degrees C falls into lake michigan, which is at a temperature of 12 degrees C. Assuming the temperature of the lake remains constant,

A) What is the entropy change of the meteor as it reaches thermal equilibrium with Lake Michigan?
B) What is the total entropy change of the universe? (meteor and Lake Michigan system)

I was able to get the first part and found the entropy change of the meteor to be -2.564E6, but I'm having trouble with part be. I think the equation I need is Entropy of universe= entropy of meteor + entropy of lake. However, I have no idea how to find the entropy of the lake. Please help. I also know the answer is 4.1E6.

Last edited by a moderator: Jan 7, 2014
2. Jul 28, 2008

### Andrew Mason

Re: Entropy

What is the expression for change in entropy? How much heat flows from the meteor to the lake? Does the temperature of the lake change during the heat transfer from the meteor to the lake? If you answer these questions, you will easily find the entropy change in the lake.

The entropy change of the meteor is a little more difficult because the temperature of the meteor is decreasing as the heat flows out of it.

AM