A metal block is placed in a room which is at 10∘C. It is heated by an electric heater of power 500 W till its temperature becomes 50∘C. Its initial rate of rise of temperature is 2.5∘C/sec. The heater is switched off and now a heater of 100 W is required to maintain the temperature of the block at 50∘C. (Assume Newton's Law of cooling to be valid). The rate of cooling in of the block at 50∘C after switching off the 100 W heater is −1n∘C/s, find n.

A metal block is placed in a room which is at 10∘C. It is heated by

1.	A metal block is placed in a room which is at 10∘C. It is heated by an electric heater of power 500 W till its temperature becomes 50∘C. Its initial rate of rise of temperature is 2.5∘C/sec. The heater is switched off and now a heater of 100 W is required to maintain the temperature of the block at 50∘C. (Assume Newton's Law of cooling to be valid). The rate of cooling in of the block at 50∘C after switching off the 100 W heater is −1n∘C/s, find n.
Answer» A metal block is placed in a room which is at $10^{\circ} C$ . It is heated by an electric heater of power $500 W$ till its temperature becomes $50^{\circ} C$ . Its initial rate of rise of temperature is ${2.5}^{\circ} C/sec$ . The heater is switched off and now a heater of $100 W$ is required to maintain the temperature of the block at $50^{\circ} C$ . (Assume Newton's Law of cooling to be valid). The rate of cooling in of the block at $50^{\circ} C$ after switching off the $100 W$ heater is ${\frac{- 1}{n}}^{\circ} C/s$ , find $n$ .