# Thread: Not sure which formula to start out with.

1. ## Not sure which formula to start out with.

An experiment involved in pouring 150g of heated copper into a 375 g aluminum cup containing 200g of water at 25 deg C. The mixture reached 28 deg C. What was the initial temp of the copper?

Is this Thermal equiliabrium?? mc delta T = mc delta T, but I have 3 items.
How do I compare 3 things?? Or do I do water to the cup and the copper to the cup??

Help if you can, thanks.

2. Looks to me like it's this simple:
Code:
200 @ 25
150 @ x
========
350 @ 28
So (200(25) + 150x) / 350 = 28

3. The answer is 89.41 deg celcius. Not sure what you did there. unless you care to explain. I can't get 89.41. I am way off on the number.

4. All I did was a simple "proportion", like:
buy 200 apples for 25 cents each, plus 150 bananas, for average price of 28 cents per fruit:
what's the price per banana?
But evidently not what you're after...
Perhaps a chemistry/physics expert will step in and help you...