|
|
| Тема |
 какво е то светкавица и какво е гръмотевица [re: pipistrellino] |
|
| Автор |
C4XPLOSlV () |
|
| Публикувано | 19.03.01 13:04 |
|
|
|
Явно не си много запознат с заобикалящия ни свят дано знаеш английски, защото сега не ми се превежда. Ето ти кратко обяснение какво е то светкавица и какво е гръмотевица:
thunder - гръмотевица
sound caused by a lightning discharge. The discharge heats and expands the air around it and forms a compression wave that is heard as thunder. The return stroke of the lightning flash produces a much louder sound than does the leader, because it transmits a more powerful electric current. Because the lightning channel is usually quite long, the thunder from the more distant portions arrives later than that from the nearer portions; this accounts for its duration. The distance to the flash may be roughly estimated by measuring the time lag between it and the thunder and allowing about five seconds per mile (three seconds per kilometre). Thunder is seldom heard at distances greater than about 15 miles (24 km)
lightning
the visible discharge of atmospheric electricity that occurs when a region of the atmosphere acquires an electrical charge, or potential difference, sufficient to overcome the resistance of the air.
...The centres of electrical charge become well established during the mature stage. The lightning that invariably accompanies a thunderstorm is a crash discharge between an upper positive centre and a lower negative centre or between one of these and the ground. Each lightning flash generally consists of several strokes in rapid sequence, with time separations of a few hundredths of a second. The sound of thunder originates in a compression wave formed along the highly heated path of a lightning stroke. Each portion of the path of a stroke releases intense sound waves, which travel different paths to the observer.
Един вид тук се казва, че това което достига до земята и носи електрически заряд е светкавицата, а гръмотевицата е причинена от светкавицата и представлява само вълнообразен шум.
| |
| |
| 
|
|
