- #1
Cantstandit
- 30
- 0
Hello,
Say I don't like to drink hot tea, in fact I don't like to drink anything hot. It is beyond my comprehension why anyone would want to drink something above 40C ;)
I have cup of hot tea 100C and i want to know how long will it take to cool down to 40C.
[tex] \frac{\Delta Q}{\Delta t}[/tex] = -k A [tex]\frac{\Delta T}{\Delta x} [/tex]
(for some reason I can't get the equation to display correctly)
so i have k of course, "delta x" would be the thickness of the mug wall, A is also given . The "delta T" part is the difference between tea and air temperature, i guess?
Now my approach would be to write an iterative algorithm, that will calculate the "instantaneous" heat flux, then lower the temperature a bit and advance time, then calculate heat flux again. Unless there is some other equation which will let me calculate it in a non-iterative way?
It seems silly that I have to iterate just to get an answer to such simple question...
This is of course if I neglect the evaporation effect, say the mug is closed, it is a fancy mug.
Say I don't like to drink hot tea, in fact I don't like to drink anything hot. It is beyond my comprehension why anyone would want to drink something above 40C ;)
I have cup of hot tea 100C and i want to know how long will it take to cool down to 40C.
[tex] \frac{\Delta Q}{\Delta t}[/tex] = -k A [tex]\frac{\Delta T}{\Delta x} [/tex]
(for some reason I can't get the equation to display correctly)
so i have k of course, "delta x" would be the thickness of the mug wall, A is also given . The "delta T" part is the difference between tea and air temperature, i guess?
Now my approach would be to write an iterative algorithm, that will calculate the "instantaneous" heat flux, then lower the temperature a bit and advance time, then calculate heat flux again. Unless there is some other equation which will let me calculate it in a non-iterative way?
It seems silly that I have to iterate just to get an answer to such simple question...
This is of course if I neglect the evaporation effect, say the mug is closed, it is a fancy mug.