Question

A piece of aluminum (specific heat 910 J/kg C) of mass 200 g at 80C is dropped into a styrofoam cup filled with 100 mL of water at 20C. What the final temperatures of the water and the aluminum? Show calculations.

I have Q=m c T
but I got 80C which I know is wrong because I set up Q1=Q2 which gave me that, could you please help me set up this problem.

Answer 1

Call final temp = T
Heat lost by Al = specific heat AL * mass of Al * (80-T)

Heat gained by water - specific heat of H2O * mass of H2O *(T-20)

Then
Heat lost by Al = Heat gained by H2O

Answer 2

right but I got 80 C both times, that cannot possibly be correct.