140 grams of boiling water (temperature 100° C, heat capacity 4.2 J/gram/K) are poured into an aluminum pan whose mass is 375 grams and initial temperature 25° C (the heat capacity of aluminum is 0.9 J/gram/K).
(a) After a short time, what is the temperature of the water?
Tfinal = 72.6499° C
(b) What simplifying assumptions did you have to make?
Energy transfer between the system (water plus pan) and the surroundings was negligible during this time.
The thermal energy of the aluminum doesn't change.
The thermal energy of the water doesn't change.
The heat capacities for both water and aluminum hardly change with temperature in this temperature range.
(c) Next you place the pan on a hot electric stove. While the stove is heating the pan, you use a beater to stir the water, doing 1300 J of work, and the temperature of the water and pan increases to 79.1° C. How much energy transfer due to a temperature difference was there from the stove into the system consisting of the water plus the pan?
Q = -1300J
thermal energy change of water + thermal energy change of aluminum = 0
thermal energy change = mC(delta T)
E = W + Q
0 = W + Q
Q = -W
The Attempt at a Solution
the answers in red are the ones i have calculated using the above equations.
need someone to confirm that i have done this correctly
only have one submission left : /