Thermodyanmics, specific heat capacity

AI Thread Summary
The discussion revolves around a thermodynamics problem involving a 4kg iron hammer at 700°C dropped into 20kg of water at 25°C. The user initially struggles with the heat transfer equation, incorrectly calculating the final temperature (Tf) and obtaining a negative value. They realize the mistake was not accounting for the heat loss of the iron hammer, which should be represented with a negative sign in the equation. After correcting this oversight, they successfully solve the problem. The discussion highlights the importance of sign conventions in thermodynamic calculations.
Jennifer001
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Homework Statement



a 4kg iron hammer is initally 700 degree celcius is droppped into a bucket containing 20kg of water at 25degree celcius. what is the final temperture



Homework Equations



q=mc(delta)T

The Attempt at a Solution



m1=4kg
m2=20kg
T1=700=973K
T2=25=298
i know the system is in equilibrium but i don't know how to solve it correctly.. so here's my shot at it

Q=mc(delta)T
=(4)(449J/kgK)(Tf-973)=(20)(4190J/kgK)(Tf-298)

i think I'm doing this question wrong because .. when i solve for Tf i get a negative number of -288.66K

help?
 
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nvm forget this question i just figured out how to do it... i forgot to put the negative sign for the iron since it loses heat.
 

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