Chapter 30, Problem 31A

In which case does light undergo the greater change in speed—traveling in air and entering a glass lens, or traveling in water and entering a glass lens?

To determine

To state: The term used to describe the energy required to raise the temperature of 1kg of a material by 1°C.

Explanation of Solution

Introduction:

Every substance absorbs different amount of thermal energy from the heat source which depends upon its own individual properties. Due to the absorption of this thermal energy, its temperature changes which depends upon the nature of the substance.

The specific heat of a material is the amount of heat energy required to raise the temperature of 1 kg of a material by 1°C. It is measured in joules per kilogram degree Celsius ( $J/kg˚C)$ . For example, water has a higher specific heat as compared to copper, it means that water can absorb more heat energy than copper without showing much rise in its temperature. It depends upon the mass of the substance, temperature change in it and also on its nature. Thus, the values of specific heat varies from one body to another body.

Conclusion:

The energy required to raise the temperature of 1 kg of a material by 1°C is a material’s specific heat.