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frasifrasi

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View Figure at http://session.masteringphysics.com/problemAsset/1042082/4/YF-17-70.jpg

1. How much heat per second flows from the steam bath to the ice-water mixture?

2. What is the length L2 of the steel section?

Now, here is my solution:

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∇q = 0

Because there is only heat flux along the rod this simplifies to:

dq/dx = 0 => q = constant

along the rod.

Heat flux is defined as

q = k·dT/dx

k is thermal conductivity

For constant q and k you find:

q = - k·ΔT/Δx

So the heat flow through the rod is

Q = A·q = -A·k·ΔT/Δx

The heat flow is constant , That means heat flow through copper section as through steel section as through the whole rod.

1.

consider copper section:

k = 400 W/Km for copper

Hence:

Q = -A·k·ΔT/Δx

= -4.00×10-4m² · 400W/Km · (65°C - 100°C) / 1m

= 5.6W

I put in 5.6, and it told me it was the wrong answer.

What did i do wrong?

Thanks.