1)Let\'s say you pour enough coffee into the mug so that the mass of coffee is e

Question

1)Let's say you pour enough coffee into the mug so that the mass of coffee is equal to the mass of the mug.  If we assume that no heat is lost to the outside room, once the mug and coffee reach the same temperature, will that temperature be closer to the initial temperature of the coffee or the initial temperature of the mug? (Notice that the  mass of the coffee and the mass of the mug are the same.)

Answer: closer to the initial coffee temperature

2)What is the final temperature of coffee and mug once they come to thermal equilibrium?
Tfinal = ____________ degrees c                 

                    3)Now lets assume that instead of the 137 g of coffee, you pour in 225 g of coffee. What is the final temperature of the coffee and mug? (Again, assume that you                    loose no heat to the outside.)

Tfinal = ____________ degrees c                 

                    4) Now lets say that along with the 225 g of coffee, you pour in 11.7 g of cream in your mug. The cream has an initial temperature of 5.2 oC and also                    has the same specific heat as water. What is the final temperature of the coffee, cream and mug? (Again, assume that you loose no heat to the outside.)
Tfinal = _____________ degrees c

Explanation / Answer

in all these problems, we need to conserve energy to get the results.so,

1)it will be closer to water since specific heat capacity of water is greater than that of coffee

2)conserving energy,

137*1.089*(T-23.8)=137*4.186*(79.8-T)

or T=68.239 C

3)conserving energy,

137*1.089*(T-23.8)=225*4.186*(79.8-T)

or T=72.14 C

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