A roast is taken from the refrigerator (where the temperature is 40 degree F) and put in a 350 degree F. One hour later, the meat thermometer shows a temperature of 90 degree F. If the roast is done when its temperature reaches 140 degree F, what is the total time the roast should be in the oven?Newton's Law of cooling says that the rate of change of temperature is proportional to the difference between the temperature of the object and the temperature of the surrounding air.