# Science:Math Exam Resources/Courses/MATH102/December 2017/Question 08

MATH102 December 2017
Other MATH102 Exams

### Question 08

A freshly laid egg has a temperature of ${\displaystyle 40}$ degrees, and the temperature outside is ${\displaystyle 10}$ degrees. After ten minutes (${\displaystyle t=10}$), the temperature of the egg is ${\displaystyle 25}$ degrees. What will the temperature be after ${\displaystyle 10}$ more minutes (${\displaystyle t=20}$)? Assume the system obeys Newton’s Law of Cooling. That is, the rate of change of the temperature of the egg is proportional to the difference in temperature between the egg and the outside. Justify your answer.

Hint: you can find an exact answer with minimal calculation (and, of course, no calculator).

 Make sure you understand the problem fully: What is the question asking you to do? Are there specific conditions or constraints that you should take note of? How will you know if your answer is correct from your work only? Can you rephrase the question in your own words in a way that makes sense to you? If you are stuck, check the hint below. Consider it for a while. Does it give you a new idea on how to approach the problem? If so, try it!

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