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.
Clouds are formed when water warms up and changes into a gas called water vapor, which rises up into the air. As it rises higher in the sky, the water vapor cools down and turns back into tiny drops of liquid. Inside the jar, some of the warm water evaporated into water vapor.