When an object is removed from a furnace and placed in an environment with a constant temperature of 80F, its core temperature is 1500F. One hour after it is removed, the core temperature is 1120F. Find the course temperature 5 hours after the object is removed from the furnace. (Hint: This is Newton's Law of Cooling problem). Please help me!

Question

anonymous · Answer

first off work with the differences in the temperatures, not the temperatures themselves

anonymous · Answer

$1500-80=1420$ and $1120-80=1040$ so it is like saying it cooled from 1420 to 1040 in one hour

anonymous · Answer

since the rate of change is proportional to the current amount (exponential decay) you can model this as $$A=\left(\frac{1040}{1420}\right)^t$$ or 
$$A=\left(\frac{52}{71}\right)^t$$ where A represents the difference in the heated temp and the ambient temp (just add 80 at the end)

anonymous · Answer

to get your answer replace $t$ by 5, and then don't forget to add the 80 degrees

anonymous · Answer

Okay, got it. Thanks again, you're a life saver!

anonymous · Answer

yw
btw you can do this a different way using 
$A_0e^{kt}$but it requires more work and is less accurate 
not sure what you teacher wants