How to Calculate Final Temperature in a Water and Aluminum System?

In summary, the problem involves pouring 160 grams of boiling water with a temperature of 100° C and heat capacity of 4.2 J/gram/K into an aluminum pan with a mass of 950 grams and initial temperature of 26° C and heat capacity of 0.9 J/gram/K. The task is to determine the temperature of the water after a short time, using the equations ΔE = ΔKsys + Δ(Msysc^2) + ΔUsys + ΔEint = Wsurr + Q and m1C1(Tf - 373.15) + m2C2(Tf - 299.15) = 0. After rearranging terms and solving
  • #1
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Homework Statement



160 grams of boiling water (temperature 100° C, heat capacity 4.2 J/gram/K) are poured into an aluminum pan whose mass is 950 grams and initial temperature 26° C (the heat capacity of aluminum is 0.9 J/gram/K).
(a) After a short time, what is the temperature of the water?



Homework Equations



ΔE = ΔKsys + Δ(Msysc^2) + ΔUsys + ΔEint = Wsurr + Q

Wsurr + Q = 0 because the surroundings aren't effecting the problem, and ΔEint isn't changing.

ΔEint = 0

So...

m1C1*ΔT + m2C2*ΔT = 0

m1C1(Tf - 373.15K) + m2C2(Tf - 299.15K) = 0




From there I don't know what to do. I know I have to solve for Tf, but I guess my problem is I don't know how to solve for Tf.

I know that Tf is the same for both of them, but that doesn't really help me solve for it. I'm probably just not thinking straight right now.

The Attempt at a Solution



Couldn't get an answer because I can't figure out how to solve for Tf.
 
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  • #2
This looks right, m1C1(Tf - 373.15) + m2C2(Tf - 299.15) = 0
so rearranging terms this gives Tf(m1C1-m2C2) = 373.15m 1C1-299.15 m2C2

Tf = (373.15 m1C1-299.15 m2C2)/(m1C1-m2C2)
 
  • #3
It took a while, but it actually equals:

Tf=373.15m1c1+299.15m2c2/m2 + c2
 

What is thermal energy?

Thermal energy is the energy an object or system possesses due to the movement of its molecules. It is a form of kinetic energy and is often referred to as heat energy.

How is thermal energy measured?

Thermal energy is measured in units of joules (J) or calories (cal). It can also be measured in units of temperature, such as degrees Celsius or Fahrenheit.

What is a thermal energy problem?

A thermal energy problem is a situation where there is a change in the amount of thermal energy in a system, resulting in a change in temperature or other physical properties.

What are some examples of thermal energy problems?

Examples of thermal energy problems include heating and cooling processes, phase changes (such as melting or boiling), and heat transfer between objects of different temperatures.

How can thermal energy problems be solved?

Thermal energy problems can be solved using principles of thermodynamics and equations such as the first and second laws of thermodynamics. These problems often involve calculating changes in thermal energy, temperature, or other properties of a system.

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