What's the Correct Temperature of the Bolt Before Placing in Water?

[Mr.Helms]

An aluminum bolt has a mass of 21.3 g. It is heated then placed into 839 g of water in a copper calorimeter cup with a mass of 137 g. The initial temperature of the water and the copper cup is 16 oC. The bolt, water and cup arive at an equilibrium temperature of 18.4 oC. What was the temperature in degrees celsius of the bolt before it was placed in the water?

I used this formula and got wrong answer, need help.

Tf = (m1C1T1 + m2C2T2) / (m1C1 + m2C2)

And got 541.3 Degrees C. What is wrong.?

 

[mufusisrad]

The first thing that pops out to me is that you have three masses exchanging heat, but your equation only accounts for two of them...

 

[robphy]

Where does this formula come from? and what do the variables mean?
Can you show more work? What did you plugged in for the various variables?

 

[ultimateguy]

Why is this in the advanced forum?