(20point) (Application of 1st order ODE : Heat Transfer)

Experiments show that the time rate of change of the temperature T of a body is proportional to the difference between T and the temperature of the surrounding medium Ts.

(a) construct a model on the temperature of the body T with respect to time t.

(b) Expressd T in terms of Ts, t and k which is the proportional constant

(c) Calculate k if at t=0, T=25'C and at t=1, T=20'C where Ts=10'C.

plz explain this question.