Question

HEAT TRANSFER ENERGY PROBLEM: The icecaps of Greenland and Antarctica contain about 1.75 % of the total water (by mass) on the earth's surface; the oceans contain about 97.5 %, and the other 0.75 % is mainly groundwater. Suppose the icecaps, currently at an average temperature of about -30.0 degrees Celcius, somehow slid into the ocean and melted.

a. What would be the resulting temperature decrease of the ocean? Assume that the average temperature of ocean water is currently 5.00 degrees Celsius.

Answer 1

I used conservation of heat energy.

Energy to raise temp of ice to 0 + energy to melt ice + energy to raise temp to final = energy loss of the ocean

Answer 2

0.0175m * c_ice * (Tf-Ti) + 0.0175m * L_f + 0.0175m * c_water * (Tf - Ti) = 0.975m * c_water * (Tf - Ti)

Answer 3

It appears that what I am doing wrong is in the right side of the equation. I have (Tf - Ti) where I need to solve for Tf, and Ti = 5 degrees Celcius, but other sources say it's supposed to be (Ti - Tf). Why is this??

Answer 4

Conservation of energy:
Energy gained by ice cube + Energy gained by sea = 0
So, Energy gained by ice cube = - Energy gained by sea
RHS = - 0.975m * c_water * (Tf - Ti) = 0.975m * c_water * (Ti - Tf)
energy loss of the ocean is not 0.975m * c_water * (Tf - Ti), this is the energy gain and is negative.
The energy loss is 0.975m * c_water * (Ti - Tf).
I hope that made sense.

Answer 5

Okay, thanks!