A1: In practice, the USB specification limits the length of a cable between full speed devices to 5 meters (a little under 16 feet 5 inches). For a low speed device the limit is 3 meters (9 feet 10 inches). Q2: Why can't I use a cable longer than 3 or 5m?
Clouds form when moist, warm rising air cools and expands in the atmosphere. The water vapor in the air condenses to form tiny water droplets which are the basis of clouds.
How thunderstorms form. Thunderstorms develop by the same process that forms cumulus clouds, the puffy clouds of summer skies. These clouds form when a humid air mass (air with an abundance of water vapor) near the surface rises on currents of air called updrafts.