Newton's law of cooling states that the temperature of an object changes at a rate proportional to the difference between its temperature and that of its surroundings. Suppose that the temperature of a cup of coffee obeys Newton's law of cooling. If the coffee has a temperature of degrees Fahrenheit when freshly poured, and minutes later has cooled to degrees in a room at degrees, determine when the coffee reaches a temperature of degrees.
The coffee will reach a temperature of degrees in minutes.