suppose the heating system of a house could, if the house were perfectly insulated, raise the temperature at a rate of 9 degrees fahrenheit an hour. However, the house is not perfectly insulated. It loses heat according to newton's Law of cooling. If the heat is turned off when the house is at 65 degrees and the temperature outside is 35 degrees, then the house temperature reaches 61 after on hour. How long does it take, from the time the heat is turned off, for the temperature of the house to reach 50 degrees.

Question

suppose the heating system of a house could, if the house were perfectly insulated, raise the temperature at a rate of 9 degrees fahrenheit an hour. However, the house is not perfectly insulated. It loses heat according to newton's Law of cooling.  If the heat is turned off when the house is at 65 degrees and the temperature outside is 35 degrees, then the house temperature reaches 61 after on hour.  How long does it take, from the time the heat is turned off, for the temperature of the house to reach 50 degrees.