Need help with heat transfe (conduction) questions!

1. Oct 2, 2012

doctordiddy

1. The problem statement, all variables and given/known data

A small pond has a layer of ice 1cm thick floating on its surface.

The air temperature is -10 C.

Steps (a-c) should help you fi nd the final answers in (d) and (e)

(a) What is the temperature of the liquid water just below the ice?

(b) Write the expression for the rate of heat transfer through the ice as a function of thickness of the ice?

(c) Write the expression for the rate of heat flow required to freeze the water?

(d) Find the initial rate in cm/hr at which ice is added to the layer.

(e) How long does it take for a 20cm layer to build up? .

2. Relevant equations

H= kA (Th-Tc)/L
H=dQ/dT

3. The attempt at a solution

For A) im not sure of the formula to use, I know only H = kA (Th-Tc)/L, but the question only provides L and Th and expects me to find Tc somehow.

For B) and C) i'm not really sure what it means by an expression (like dQ/dt = kA (Th-Tc)/L?)
would B) be like dH(L) = kA(Th-Tc)?

For D) i have the save problem as in question A) where I do not feel I have enough variables to solve for dQ/dt

i think i can probably solve for e) once I get the other parts.