Question

At a common temperature, a block of wood and a block of metal feel equally cool or hot. The temperatures of metal and wood are
A. Less than the temperature of the body
B. Equal to the temperature of the body
C. Greater than the temperature of the body
D. Either A or C

Answer 1

Hint: In order to solve this problem we need to understand the rate of heat transfer and thermal equilibrium. The rate of flow of heat is the amount of heat that is transferred per unit of time temperature. Thermal equilibrium relates between two bodies or closed systems. Two objects are said to be in thermal equilibrium if they are in close contact that allows either to gain energy from the other, but no net energy is transferred between them.

Complete step by step solution:
They said that at a common temperature, a block of wood and a block of metal feel equally cool or hot. Then we need to discuss how the temperatures of metal and wood vary. As both the block of metal and the block of wood feel equally cold or hot, their temperatures should be equal to the temperature of the body.

Or else there will be heat flow between the body and either of the blocks. The thermal conductivity of the metal is more than that of the wood, it would either feel hotter or colder than the block of wood.

Hence, option B is the correct answer.

Note: It does not matter whether a solid is made up of conducting and non-conducting material. Given enough time to transmit the heat from the hot side to the cold side, the solid body will reach thermal equilibrium.