SOLUTION: Use Newton's Law of Cooling, T=C+(Tsubscript0 - C)e^kt to solve the below: A pizza removed from the oven has a temperature of 450 degrees Fahrenheit. It is left sitting on a room

Algebra.Com
Question 1161289: Use Newton's Law of Cooling, T=C+(Tsubscript0 - C)e^kt to solve the below:
A pizza removed from the oven has a temperature of 450 degrees Fahrenheit. It is left sitting on a room that has a temperature of 70 degrees Fahrenheit. After 5 minutes, the temperature of the pizza is 315 degrees Fahrenheit.
a. Use Newton's Law to find the model for the temperature of the pizza T, after t minutes.
answer: 315 = 70 + (5mins - 450)e^kt
b. What is the temperature of the pizza after 25 minutes?
answer - ???
c. When will the temperature of the pizza be 130 degrees Fahrenheit?
answer: ???

Answer by KMST(5328)   (Show Source): You can put this solution on YOUR website!
I bake frozen pizzas for my husband very often, so I can figure this out.
=temperature at time
=temperature at time
=ambient temperature
The units we use for and for the temperatures do not matter as long as we are consistent.
At makes
As approaches ,
needs to approach ,
so that approaches ,
so the constant must be a negative number.

a. With time in minutes and temperature in degrees Fahrenheit,
the data gives us the equation ,
or , if we simplify.
We need to find , and substitute its value into
to find the model
(a formula we can use to figure out how long to wait for that pizza to cool).



I could use (or a rounded version of that) in the next equation, but I will let the calculator remember the number and keep crunching numbers.


According to my scientific calculator,
} (rounded to 4 significant figures).
So, the model is
b. After 25 minutes ,
so we substitute that value into our model to find for that pizza.
From experience, I say we waited too long.


Using rounded values, ,so
, and continuing to round, ,
so
After 25 minutes, the temperature of the pizza is .

c. To find out when the temperature of the pizza will be
(in degrees Fahrenheit), we substitute that into our model, getting
as the equation to solve.





and according to my calculator, .
So, according to our model, to eat the pizza at , we have to wait .

RELATED QUESTIONS

A pizza pan is removed from an oven whose temperature is a fixed 450F to a room that is a (answered by ikleyn)
A coroner found that the temperature of a murdered body was 90 F at 11:00 pm and 88.5 F... (answered by solver91311)
A coroner found that the temperature of a murdered body was 90 F at 11:00 pm and 88.5 F (answered by Boreal)
Solve the problem. A thermometer reading 9°C is brought into a room with a constant... (answered by KMST)
A car engine runs at a temperature of 87°C, when the engine is turned off, it cools... (answered by math_tutor2020,Theo)
According to Newton's Law of Cooling, if a body with temperature T 1 is placed in... (answered by Fombitz)
Oh why are Newton's Law of Cooling problems so confusing to me anyways here is another... (answered by richwmiller)
Newton’s law of cooling states that the rate of cooling of an object is proportional to... (answered by robertb)
Newton’s law of cooling states that the rate of cooling of an object is proportional to... (answered by Fombitz)