Newton's Law of Cooling states that the rate of cooling of an object is proportional to the temperature difference between the object and its surroundings. Suppose t is time, T is the temperature of the object, and Ts is the surrounding temperature. The following differential equation describes Newton's Law:
dT/dt = k(T - Ts),
where k is a constant.
Suppose that we consider a 98°C cup of coffee in a 20°C room. Suppose it is known that the coffee cools at a rate of 2°C/min. when it is 70°C. Answer the following questions:
1. Find the constant k in the differential equation. Answer (in per minute): k =
2. What is the limiting value of the temperature? Answer (in Celsius): T =
3. Use Euler's method with step size h = 2 minutes to estimate the temperature of the coffee after 10 minutes. Answer (in Celsius): T(10) ≈