MixedHardQuestion 370012
Question
Newton's law of cooling: dT/dt = −k(T−T₀). After solving, T(t) is:
- AT₀ + (T_initial − T₀)e^(−kt)Correct
- BT₀ × e^(−kt)
- CT_initial × e^(−kt)
- DT₀ + T_initial e^(kt)
Correct answer
T₀ + (T_initial − T₀)e^(−kt)
Explanation
dT/dt = −k(T−T₀). Let u = T−T₀: du/dt = −ku → u = Ae^(−kt) → T−T₀ = (T_i−T₀)e^(−kt) → T = T₀ + (T_i−T₀)e^(−kt). As t→∞, T→T₀.