Chapter 31, Problem 19RQ

To determine

The development of thunder and lightning.

Answer to Problem 19RQ

The lightning develops due to the attraction between the negative charges of the base of the cloud and the positive charges on the ground. As a result, the electric current is produced that appears as lightning. Thunder develops due to the expansion of air by the heating effect of electric current.

Explanation of Solution

Due to the crashing of clouds and turbulence of the air, the negative charges accumulate on the base of the clouds and the positive charges accumulate on the top of the surfaces. The negative charges on the base of the surface of the clouds attract the positive charge on the ground due to opposite charges. These electric charges accumulated enough to make the air, conducting and when they meet, they form an electric current that forms lightning.

The electric current flows down towards the Earth’s surface. Due to the heating effect of electric current, the air expands rapidly and sound produces due to this effect and this sound is known as thunder.

The lightning and thunder produce at the same time, but as the speed of the light is greater than the speed of the sound, so lightning is seen before the thunder is heard.

Conclusion:

Therefore, the lightning develops due to the attraction between the negative charges of the base of the cloud and the positive charges on the ground. As a result, the electric current is produced that appears as lightning. Thunder develops due to the expansion of air by the heating effect of electric current.