Find the Final Temperature of Metal and Water in a Thermodynamics Problem

[physicsman2]

1. Homework Statement
A 100-g piece of metal initially at T = 75oC is submerged in 100 g of water initially at T = 25oC. The specific heat capacity of iron is 0.45 J g-1 °C-1 and the specific heat capacity of water is 4.18 J g-1 °C-1. What is the final temperature of both substances in oC?


2. Homework Equations
q=mc(delta T)


3. The Attempt at a Solution
well i tried to set mc(delta T)=mc(delta T), plug in all the values and solve for T(final), but i keep getting the wrong answer

 

[rock.freak667]

What numbers did you put for each of the changes in temperature?

 

[physicsman2]

mc(delta T)=mc(delta T)

(100)(.45)(T(final)-75)=100(4.184)(T(final)-25)

i solved that for T(final) but still got the wrong answer

 

[rock.freak667]

mc(delta T)=mc(delta T)

(100)(.45)(T(final)-75)=100(4.184)(T(final)-25)

i solved that for T(final) but still got the wrong answer

For the term on the left side, (the metal at 75), it can't gain heat, it only loses heat. So That should be (75-T_final). Understand?

 

[physicsman2]

oh, now i understand, thank you so much