Temperature at the tip of a fin

[theBEAST]

Homework Statement

The Attempt at a Solution

I initially found the temperature tip without accounting for the corrected length. But the solution uses the corrected length for finding the temperature which doesn't make sense to me. Don't we want the temperature at the tip L, if we find the temperature at the corrected length then that isn't the ACTUAL temperature, it is an approximation we use to find efficiency I thought?

Both answers are pretty close, only off by around 0.01 C.

Here is my solution along with the relevant equations:

Here is the textbook solution:

 

[BvU]

Dear animal,

Love this exercise. Can't get up to speed quick enough, so can't help you. Do find it interesting you worry about .01 degree if h is given in 1 decimal. Just try to imagine how hard it is to establish this h !

Interesting thread, will look at what comes out.