Given below are the four cases in which certain heat transfer is taking place: 1. Ice is melting in a glass full of water 2. Water is boiling in an open container 3. A metal rod is heated in a furnace 4. A cup of coffee is allowed to cool on a table In which of the above cases, the Newton's Law of Cooling is appli- cable?

Correct option is B

The correct answer is (b) 4 only. Explanation: Newton's Law of Cooling applies when an object cools by losing heat to its surrounding environment. The law states that the rate of heat loss of an object is proportional to the temperature difference between the object and its surroundings. This situation matches Case 4, where a cup of coffee is cooling on a table. The coffee loses heat to the cooler surrounding air, and the cooling rate depends on the temperature difference between the coffee and the air. Analysis of Other Cases: · Case 1 (Ice melting): Involves heat absorption, not heat loss, so Newton’s Law of Cooling doesn’t apply. · Case 2 (Boiling water): Involves constant heat input to maintain boiling, which doesn’t fit Newton’s Law. · Case 3 (Heating a metal rod): Involves heat gain rather than loss, so it doesn’t apply here. Therefore, Newton's Law of Cooling is applicable only to Case 4.