2007-05-13 12:52:45 · 6 answers · asked by spindymindi 3 in Science & Mathematics ➔ Physics
There are several answers to this question depending on what you mean by "the speed of electricity". If you mean how fast electricity travels in a wire (the propogation velocity), that is about 60% of the speed of light. This is the speed that governs the time it takes for a light to go on after you flip the switch.
The actual velocity of electons in the wire is very slow (drift velocity) and is only a few mm per second. It is the average speed of all the electrons in the wire under the influence of the voltage applied. The speed of an individual electron at any moment is much higher (peak velocities reach 10^5m/s), but the average of all of them is slow, since they are moving in all directions.
Finally, electricity can travel in the form of electromagnetic waves (radio waves, microwaves, light) and in this form travels at exactly the speed of light.
2007-05-13 12:59:57 · answer #1 · answered by gp4rts 7 · 0⤊ 0⤋
Electrons travel at a very slow rate based on the potential (difference in voltage). For a typical 100 watt bulb powered by USA alternating current (120VAC), electricity moves at 8.6 cm/ hour. An electric arc like lightning travels at a paltry 10,000 feet per second. And that is a huge potential of 100,000 volts to a million volts.
Light travels at 186,000 miles per second.
When electrons move, they set up a disturbance in the electromagnetic field of the medium (copper wire, air, the skin film of a human or other object). That disturbance, or signal, travels at the speed of light for the medium. That is why there is no perceptible delay when you switch a light "on." When one electron moves in a wire, no matter how small the movement, other electrons will respond to that movement and move to fill the void left by the single moving electron. Electrons in the switch may never arrive at the light bulb, but electrons in the filament will start to move as soon as the switch is clicked.
2007-05-13 20:07:12 · answer #2 · answered by Owl Eye 5 · 0⤊ 0⤋
The signal travels at lightspeed divided by the square root of the surrounding dielectric constant. In vacuum use permittivity of free space.
The electrons themselves travel a few mm/sec at most - one electron/copper atom in the conduction band and 96,485 coulombs/mole electrons. Take a 1 cm length of wire, work out its mass then the number of moles of copper in it. Inject your current for second. How far into the wire did you displace electrons?
2007-05-13 20:17:25 · answer #3 · answered by Uncle Al 5 · 0⤊ 0⤋
Speed of light
2007-05-13 20:00:02 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Depends on the medium through which it travels.
2007-05-13 19:59:57 · answer #5 · answered by mcd_48230 3 · 0⤊ 0⤋
You need to clarify what exactly you mean.
2007-05-13 19:57:07 · answer #6 · answered by Anonymous · 0⤊ 0⤋