Résultats de recherche
Il y a 20 heures · Dipole antenna used by the radar altimeter in an airplane. Animated diagram of a half-wave dipole antenna receiving a radio wave. The antenna consists of two metal rods connected to a receiver R. The electric field ( E, green arrows) of the incoming wave pushes the electrons in the rods back and forth, charging the ends alternately positive ...
Il y a 20 heures · A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people over cargo. [1] [2] The French inventor Nicolas-Joseph Cugnot built the first steam-powered road vehicle in 1769, while the Swiss inventor François ...
Il y a 20 heures · Definitions. A tornado is a violently rotating column of air, in contact with the ground, either pendant from a cumuliform cloud or underneath a cumuliform cloud, and often (but not always) visible as a funnel cloud. [20] For a vortex to be classified as a tornado, it must be in contact with both the ground and the cloud base.
