Physics Circle home Student Login

Home›Chapters›Heat Transfer and Radiation PYQs›Newton's Law of Cooling›Question 16

MHT CET 2023 (14 May, Shift 2) · Newton's Law of Cooling

Newton's Law of Cooling question from MHT CET 2023 (14 May, Shift 2)

Q16MHT CET 2023 · 14 MAY · SHIFT 2Medium

Newton's Law of Cooling

A metal rod cools at the rate of 4∘C/min4^\circ\text{C/min} when its temperature is 90∘C90^\circ\text{C} and the rate of 1∘C/m1^\circ\text{C/m}in when its temperature is 30∘C30^\circ\text{C}. The temperature of the surrounding is

Show answer and solution

Answer: (c)

  1. Newton's law: rate ∝(T−θ0)\propto (T - \theta_0).
  2. 41=90−θ030−θ0\frac{4}{1} = \frac{90 - \theta_0}{30 - \theta_0}
  3. 120−4θ0=90−θ0⇒θ0=10∘120 - 4\theta_0 = 90 - \theta_0 \Rightarrow \theta_0 = 10^\circC
  4. So the answer is (c) 10∘10^\circC.
Report a mistake

More questions on Newton's Law of Cooling