At room temperature of 30 degree celsius, a glass of water takes one minute to cool from 80 degree celsius to 60 degree Celsius. How long will it take to further cool from 60 degree celsius to 50 degree celsius?

3 answers

Well from 80 to 70 to 60 is three twenty seconds. 20+20+20=100 (one minute) so from 60 to 50 is 20 seconds. Answer: It will take 20 seconds to cool from 60 degree Celsius to 50 degree Celsius.
newtons law of cooling applies:

http://www.softschools.com/formulas/physics/newtons_law_of_cooling_formula/93/

from the data of room temp, 80 to 60, determine rate r.
then put that in the formula to figure time from 60 to 50.

If you need help with this calculation, ask.
thank you bobpursley