Physics – 2.3.3 Radiation | e-Consult

When the thermometer is placed in the hot water, thermal energy is transferred from the water to the thermometer. The water is at a higher temperature than the thermometer initially, so heat will flow from the hotter water to the cooler thermometer. This heat transfer occurs through conduction, as the thermometer and water are in direct contact.

As the thermometer absorbs thermal energy, its internal energy increases, and its temperature rises. The rate at which the thermometer's temperature rises depends on its heat capacity and specific heat capacity. The heat capacity is the amount of heat a substance can absorb before its temperature changes by a certain amount. The specific heat capacity is the amount of heat required to raise the temperature of 1 kg of a substance by 1°C. A lower specific heat capacity means the temperature changes more readily for a given amount of heat.

The heat transfer continues until the thermometer and the water reach thermal equilibrium. At thermal equilibrium, the thermometer and the water have the same temperature, and there is no net transfer of thermal energy between them. The thermometer reading will increase until it reaches the temperature of the water, and then it will remain constant. The final temperature will depend on the initial temperature of the water, the mass of the water, and the specific heat capacity of the water.