Is a Rate of 100K/s an Intuitively Offensive Way to Measure Temperature Change?

AI Thread Summary
The discussion centers around the appropriateness of measuring temperature change at a rate of 100K/s in thermal physics. Participants agree that while the approach to the problem is correct, the resulting temperature change is excessively high, being three orders of magnitude too large. The calculations indicate that with a power input of 10,000 J per second, the temperature would indeed rise by approximately 100 K each second, which is deemed intuitively offensive. The consensus is that such a rapid rate of heating is unrealistic and would not be sustainable. Overall, the conversation emphasizes the need for careful attention to detail in thermal calculations.
Bolter
Messages
262
Reaction score
31
Homework Statement
Thermal physics
Relevant Equations
Q=m*c*deta t
Question:

Screenshot 2019-12-06 at 17.04.12.png

This would be the right approach to do this problem?
IMG_3423.JPG


Thanks!
 
Physics news on Phys.org
Bolter said:
Homework Statement:: Thermal physics
Homework Equations:: Q=m*c*deta t

Question:

View attachment 253759
This would be the right approach to do this problem?
View attachment 253760

Thanks!
Correct approach. Incorrect result.
 
Bystander said:
Correct approach. Incorrect result.
Why is it an incorrect result?
 
Bolter said:
Why is it an incorrect result?
I think your answer is correct. I hope I'm not overlooking something trivial.
 
Three orders of magnitude too large.
 
Bystander said:
Three orders of magnitude too large.
Note that the power input is given in kilowatts.
 
TSny said:
in kilowatts.
..., and mass in kilograms.
 
Bystander said:
..., and mass in kilograms.
Yes. From m and c you can see that it takes about 100 J to raise T by 1 K. Heat is going in at about 10,000 J each second. So T will increase about 100 K each second.
 
o:). Looking at the faint decimal point in "nine point eight one" and figuring he'd missed that in his computation; wasn't paying attention...100K/s? Intuitively offensive, but...o:)o:)
 
  • Like
Likes TSny
  • #10
Bystander said:
...100K/s? Intuitively offensive
Yes. That rate of heating would not last long. :oldsmile:
 
Back
Top