The characteristic wavelength of an electron = h / p, where
h = Planck's constant;
p = the electron linear momentum = electron mass * speed = g * electron rest mass * speed; and
g = the Lorentz factor to account for the electron-mass change with speed.
Known facts:
h = 6.63 × 10-34 [J s]
electron rest mass, me = 9.11×10-31 [kg]
electron speed, v = 1.5x108 [m/s]
c = speed of light in vacuum = 3x108 [m/s]
v/c = 0.5
g = 1/sqrt(1 - v2/c2) = 1/sqrt(0.75) = 1.1547
Therefore, p = 1.1547 * 9.11×10-31 [kg] * 1.5x108 [m/s] = 2.7e-29 [kg m s-1]
Hence, the electron wavelength
= 6.63 × 10-34 [J s] / 2.7e-29 [kg m s-1]
= 2.46e-5 [m] or 2.46x10-5 [m].
Q.E.D.
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c/2 = 149,896,229 meters (93,141.2 miles) per second, in vacuum.
In material media, divide this number by the refractive index of the medium
to find one half of the speed of light in that medium.
No. Light travels at about 875 thousand times the speed of sound.
One Light Year at Snail Speed was created in 2003.
Albert Einstein postulated that all observers, no matter what their velocity relative to the emitter of the light, will measure the light speed from that emitter as exactly the same as any other observer. The implicatons of this postulate have been proven to be true in every one of countless experiments in the decades since he made that postulate.
The distance in meters covered by light in one second is considered to determine the speed of light. Speed of light is 3*108m/s. The unit of speed of light is meters per second.
Well, it takes 2,700 years for light to travel that far. Anything travelling at half light-speed would take 5,400 years. At 1/4 light-speed, it would take 10,800 years.
No. Light travels at about 875 thousand times the speed of sound.
Well, if it is a particle of light (a photon) it takes about a second and a half. If it is any other particle, one that does not move at the speed of light, then you have to define a speed for it.
No. Not even one thousandth of the speed of light.
The speed of light is always the same, as long as the light stays in vacuum or in the material substance it's in. The speed of the source generating the light, or the speed of the person who's measuring the light, has no effect on the light's speed. It will always measure the same number. That means: -- If a rocket is in space, flying toward you at half the speed of light, and the astronaut aboard shines a flashlight at you, and -- If you strap a jet-pack on your back and fly toward the rocket at half the speed of light, and -- If you measure the speed of the light from his flashlight as it shines past you, -- You'll measure the same speed of light as if you and the astronaut were both standing still. It can't be . . . But it is. It's been confirmed in thousands of experiments during the past 100 years.
One half the speed of the crankshaft.
According to Ecclesiastes, Sin travells at twice the speed of light and half the speed of bad news.
One Light Year at Snail Speed was created in 2003.
The distance in meters covered by light in one second is considered to determine the speed of light. Speed of light is 3*108m/s. The unit of speed of light is meters per second.
Albert Einstein postulated that all observers, no matter what their velocity relative to the emitter of the light, will measure the light speed from that emitter as exactly the same as any other observer. The implicatons of this postulate have been proven to be true in every one of countless experiments in the decades since he made that postulate.
The light doesn't change. But by cutting the time in half that the shutter stays open,you cut in half the total amount of light that reaches the film.
No, not quite. We know that for sure, because nothingmoves faster than the speed of light.
One and a half. One to turn the light bulb, and half of one to provide applause.