Heat Transfer

Question

heat diffused in our tuna steak was about 12 mm in 5 minutes. Using these values for L and for t, calculate the value of D for this time point. Enter your answer in cm2/sec, without including the units.

Answer 1

See https://en.wikipedia.org/wiki/Rate_of_heat_flow
Post your work if you get stuck.

Answer 2

Explanation

The diffusion equation states that L2=4Dt. Using 1.2 cm and 300 seconds:

1.44 cm2 = 4D x 300 sec

0.0012 cm2/sec = D

This is the explanation.. but I don't understand how to get that Dr Bob

Answer 3

Assuming that is L² and not L*2, you have D and what's to understand. That's your answer in cm^2/sec.

Answer 4

My Question Dr Bob

how do I get 0.0012 cm2/sec
Which calculation should I do to get that number?

Sorry my clumsiness

Answer 5

The problem states 12 mm for L. Convert to cm to get 1.2 cm and L^2 = 1.2cm*1.2cm = 1.44 cm^2.
Then 1.44 cm^2 = 4D x 300 sec
D = 1.44 cm^2/4*300 sec= 0.0012 cm^2/sec

Answer 6

Clear enough now.

Thanks Dr Bob