Question 48117This question is from textbook College Algebra
: A kettle full of water is brought to a boil in a room with temperature 20C. After 15 minutes the temperature of the water has decreased from 100C to 75C. Find the temperature after another 10 minutes, and sketch a graph of the temperature function.
Thank you so much! Does this have anything to do with Newton's Law of Cooling and the formula T(t) = Ts + D0e^-kt? My calculator simply will not do this.
This question is from textbook College Algebra
Answer by cowess(34)   (Show Source):
You can put this solution on YOUR website! 10/15*(100-75)=(2/3)*25=16.67
75-16.67=58.33
suppose y is the temperature of the water in the kettle,
x is the amount of time after the water was boiled.
So y=100-25(x/15), but the water will stay at room temperature and cease to decrease so when y=20, x=((100-20)/25)*15=(16/5)*15=48
The line on the graph change directions after x=48
1)48>=x>=0, y=100-25(x/15)
2)x>=48, y=20
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