Question

1.

Consider an insulated container with an interior made of metal (such as a travel mug). Coee at the boiling temperature of water is added to the container along with a smaller amount of cream. Assume the metal liner and cream were initially at 20C (so Ti;met = Ti;cr = 20C).

(a) When the system reaches equilibrium, what is the relation between the heat absorbed by the three components Qcf ; Qmet; and Qcr? (i.e. give the sign of each term and say if one term is much larger in magnitude than the others). Note Qcf refers to heat absorbed by the coee.

(b) Denote the masses and specic heats of the metal, cream, and coee by mmet; mcr; mcfand cmet; ccr; ccf . Find the general formula for the equilibrium temperature in terms of these quantities and the initial temperatures Ti;met; Ti;cr; Ti;cf .

(c) Suppose the specic heat of the metal is: Cmet =(1/10)ccf which is quite reasonable, and that the specic heat of cream is the same as coee, ccr = ccf . Let the relation between the masses of the metal, cream, and coee be: Mmet = mcr =(1/10)mcf . Using this information, and your answer from part (a), what is the equilibrium temperature in degrees Celsius?

Answer 1