Newton’s law of cooling says that the temperature of a body changes at a rate proportional...

Newton’s law of cooling says that the temperature of a body changes at a rate proportional to the difference between its temperature and that of the surrounding medium (the ambient temperature),

where T = the temperature of the body (°C), t = time (min), k = the proportionality constant (per minute), and T_a = the ambient temperature (°C). Suppose that a cup of coffee originally has a temperature of 70 °C. Use Euler’s method to compute the temperature from t = 0 to 20 min using a step size of 2 min if T_a = 20 °C and k = 0.019/min.