What is the temperature inside the freezer?

[AllenHe]

Homework Statement

A piece of copper of mass 170g is cooled in a freezer. it's then dropped into water at 0degree,causing 4 g of water to freeze.determine the temperature inside the freezer.

Homework Equations

The Attempt at a Solution

 

[grzz]

Is all the water frozen?

 

[AllenHe]

Nnly 4g

 

[grzz]

try conservation of energy principle:
ignoring heat losses to the surroundings, then
energy guven out by copper = energy gained by water

 

[AllenHe]

Okay.But I don't understand that formula.Can you explain to me?