# Which material is a heat source for the other three materials?

Presented is a closed energy system containing equal masses of iron (55 degrees C), basalt (45 degrees C), and water (20 degrees C); air is 30 degrees C.

Which material is a heat source for the other three materials? 1) iron 2) basalt 3) air 4) water - Is the answer iron because it has the most heat?

During the first hour, the total energy in the system will 1) decrease, only 2) increase, only 3) decrease, then increase 4) remain the same - (Shouldn't it remain the same because of the conservation of energy?)

Also during the first hour, the temperature of the water will 1) decrease 2) increase 3) remain the same - (I think it will increase because it acts as a heat sink? Or maybe it will remain the same because water has the highest specific heat?)

Helping me understand one or all of these would be a great help!

As far as my knowledge extends,

1st Question: 1. Iron (reason you've given).

2nd Question: 4. Remains same (Law of Conservation of Energy)

3rd Question: 2. Increases, as the system will try to reach a proper equilibrium at a fixed temperature, given by the Principle of Calorimetry.

• the Homework-and-exercises tag info page says you ought to focus on the method of getting the answer rather than providing the answer. Also I don't think the explanation for Q1 is using the right words.
– user118047
Apr 5, 2017 at 22:42
• I don't exactly know how to go about focusing on the method other than what I put in parenthesis. We are allowed to work together on these problems with a partner but I do not have any friends like everyone else in the class and the professor does not respond to emails; I don't know how else to go about solidifying these concepts... Apr 5, 2017 at 22:56
• Actually I'm just going to delete my account, I have given up lol. Thank you both of you for your help but I don't think I am what this community wants, thank you again. Apr 5, 2017 at 22:58