Final answer:
Thunderstorms form from rising moist air that condenses into clouds. Electric fields within these clouds give rise to lightning when they become large and reversed. A lightning strike's energy varies with the height of the clouds, analogous to a cloud-ground system acting as two parallel plates.
Step-by-step explanation:
Formation of Thunderstorms and Lightning
The formation of thunderstorms begins with rising moist air, which cools and condenses to form clouds and potentially storm conditions. When the localized electric fields within the clouds become large and possibly reversed, this sets the stage for the development of lightning. A thunderstorm cloud can act like a giant capacitor, with different parts of the cloud and ground holding opposite charges. Lightning occurs when a significant electrical breakdown happens between these charges, resulting in an enormous discharge of electricity.
As for the calculation of the distance to a lightning storm after seeing the lightning and hearing thunder 5 seconds later, we use the fact that light travels at 3 × 108 m/s and sound travels much slower, at about 343 m/s (speed depending on air temperature). This time difference allows us to estimate the distance of the storm to be approximately 1,715 meters away (5 seconds × 343 m/s).
A lightning rod works by providing a path of least resistance for the lightning to travel to the ground, thus protecting the structure it is attached to.
Concerning safety during a lightning storm, a metal car can provide protection, acting like a Faraday cage, which shields the passengers inside from external electric fields. Similarly, a downed power line touching a car forces the electric charge to remain on the outer surface of the car, sparing the occupants from the electric field.
Energy of a Lightning Strike
The energy of a lightning strike is related to the height of the clouds since the cloud-ground system acts as two parallel plates, with the potential energy being proportional to the separation distance. The greater the height, the greater the potential difference, and thus the more energy that is released in a lightning strike.