Light and Heat

21.1 Refraction of light
Light travels in straight lines. However, when it travels from one medium to another for example, from air to water, it bends.

Dispersion of light through a prism
White light is actually made up of many different colors. we can prove this by shining white light through a prism.A prism a transparent plastic or glass object, with smooth flat sides that can refract light.

Dispersion of light through water droplets
Water droplets in the air can act as tiny prisms. The droplets can be from the rain, the mist of a waterfall or a fine spray of water from a garden house.

21.2 Transfer of heat
Just a light travels from one medium to another, heat also travels from one object or place to another. Heat travels from a region of higher temperature to a region of lower temperature through conduction, convection and radiation.

Conduction
Heat can transfer from one part to another within an object or between objects. This type of heat transfer is called conduction.

Convection
The transfer of heat from one region to another by the movement of fluids is knows as convection.

Radiation
Radiation is release of heat from the surface of most bodies that is transferred directly from one region to another.