- #1
Jeffopolis
- 12
- 0
First of all, hi, and thanks ahead of time... I've been working on this homework for almost a week, even asked the teacher for help but still haven't been able to figure out what I've been doing wrong/missing. its online work so ill copy paste it
(a) Two 32 g ice cubes are dropped into 170 g of water in a thermally insulated container. If the water is initially at 27°C, and the ice comes directly from a freezer at -13°C, what is the final temperature (in Celsius) at thermal equilibrium? (b) What is the final temperature if only one ice cube is used? The specific heat of water is 4186 J/kg·K. The specific heat of ice is 2220 J/kg·K. The latent heat of fusion is 333 kJ/kg.
Q = cm(delta T)
Q = Lm
where c = specific heat, T = change in temp, m = mass of object, L = heat of fusion/vaporization
I have a few questions that are similar but i think if i can solve one, then I'd be able to solve the others... I am not going to paste all my attempts because it'd take up 4 pages but ill summarize what i did
basically i know that:
0 = Q1 + Q2 + ... + Qn for all objects, since its in equilibrium/isolated location...
I'm assuming that there being 2 ice cubes, there will be 3 Q's
Q1 = water, cm(delta T) = 4186 * 170g * (Tfinal - 27)
Q2 = ice, cm(delta T) + heat of fusion?? [this part I am not sure if I am doing right] --- cm(delta T) + Lm = 2220 * 32 * (Tfinal +13) + 333 * 32
Q3 = same as Q2
adding em together and what not, i get:
Tfinal = (18279564 / 782660) = ~20.2ish... all my answers have been between like 20-20.5 for A and about 23 for B, neither of which have been right (there is a +/- 1 degree of error for part B, A must be exact)
Umm i have one more attempt to get the right answer on this one so yea... any help is greatly appreciated. It's due sunday and i have a gig tomorrow and sunday so whatever help i can get as soon as possible would be amazing
thanks again
Homework Statement
(a) Two 32 g ice cubes are dropped into 170 g of water in a thermally insulated container. If the water is initially at 27°C, and the ice comes directly from a freezer at -13°C, what is the final temperature (in Celsius) at thermal equilibrium? (b) What is the final temperature if only one ice cube is used? The specific heat of water is 4186 J/kg·K. The specific heat of ice is 2220 J/kg·K. The latent heat of fusion is 333 kJ/kg.
Homework Equations
Q = cm(delta T)
Q = Lm
where c = specific heat, T = change in temp, m = mass of object, L = heat of fusion/vaporization
The Attempt at a Solution
I have a few questions that are similar but i think if i can solve one, then I'd be able to solve the others... I am not going to paste all my attempts because it'd take up 4 pages but ill summarize what i did
basically i know that:
0 = Q1 + Q2 + ... + Qn for all objects, since its in equilibrium/isolated location...
I'm assuming that there being 2 ice cubes, there will be 3 Q's
Q1 = water, cm(delta T) = 4186 * 170g * (Tfinal - 27)
Q2 = ice, cm(delta T) + heat of fusion?? [this part I am not sure if I am doing right] --- cm(delta T) + Lm = 2220 * 32 * (Tfinal +13) + 333 * 32
Q3 = same as Q2
adding em together and what not, i get:
Tfinal = (18279564 / 782660) = ~20.2ish... all my answers have been between like 20-20.5 for A and about 23 for B, neither of which have been right (there is a +/- 1 degree of error for part B, A must be exact)
Umm i have one more attempt to get the right answer on this one so yea... any help is greatly appreciated. It's due sunday and i have a gig tomorrow and sunday so whatever help i can get as soon as possible would be amazing
thanks again