What is the speed of the light being emitted from the headlights of a Stationary car & what is the speed of the light being emitted from a car travelling at 100 miles an hour ?
2007-02-22 18:37:11 · 17 answers · asked by Tim 3 in Science & Mathematics ➔ Physics
If an apple is on the ground then its got zero velocity, when the same apple is in a car moving at 100 miles an hour, then the apple too is going 100 miles an hour.
In the same way the speed of light from the moving car will be = speed of light + 100 miles per hour
2007-02-22 22:20:43 · answer #1 · answered by Anonymous · 0⤊ 4⤋
You want to know what's really weird? The speed of light from from a moving car doesn't just travel at the same speed as that from a stationary one, It doesn't matter whether you measure it from the roadside or inside the moving car. They both get 3x10^8m/s.
The speed of light is the same for all observers regardless of how they move relative to each other (relativity). To make this work, Einstein showed that time itself has to slow down as you move faster.
If that sounds stupid, consider the alternative
A car moving towards you would have light moving faster than light coming from a car moving away from you. So if they crashed into each other, the light from the car coming towards you would arrive before the light from the other car. You see one crash into...nothing, then a bit later the other would crash into the first car.....Now THAT doesn't make sense. Given this as an alternative, its probably best that the speed of light is the same for everyone, everywhere.
2007-02-23 09:17:22 · answer #2 · answered by BIMS Lewis 2 · 0⤊ 0⤋
One consequence of the laws of electromagnetism (such as Maxwell's equations) is that the speed c of electromagnetic radiation does not depend on the velocity of the object emitting the radiation; thus for instance the light emitted from a rapidly moving light source would travel at the same speed as the light coming from a stationary light source (although the colour, frequency, energy, and momentum of the light will be shifted, which is called the relativistic Doppler effect). If one combines this observation with the principle of relativity, one concludes that all observers will measure the speed of light in vacuum as being the same, regardless of the reference frame of the observer or the velocity of the object emitting the light. Because of this, one can view c as a fundamental physical constant. This fact can then be used as a basis for the theory of special relativity. It is worth noting that it is the constant speed c, rather than light itself, which is fundamental to special relativity; thus if light is somehow manipulated to travel at less than c, this will not directly affect the theory of special relativity.
Observers travelling at large velocities will find that distances and times are distorted ("dilated") in accordance with the Lorentz transforms; however, the transforms distort times and distances in such a way that the speed of light remains constant. A light sensor travelling near the speed of light would also find that colours of lights ahead were shifted toward the violet end of the spectrum and of those behind were redshifted, so that the Lorentz transformations and classical explanations of shifting are in harmony.
2007-02-23 02:47:34 · answer #3 · answered by waway_bato2005 2 · 2⤊ 0⤋
Speed of light is always the same in a vacuum, as others have said.
FYI, if you actually conducted the test outside your home using two identical light sources, the light from the car would move slightly slower due to doppler shifting to a higher frequency. Speed of light varies inversely with frequency in a transparent medium.
2007-02-23 03:18:14 · answer #4 · answered by SAN 5 · 1⤊ 0⤋
They are both the same. Travelling at speed does not make light travel any faster
2007-02-23 09:08:51 · answer #5 · answered by rose 3 · 0⤊ 0⤋
The light moves away from the car @ the speed of light. Whether it is moving or standing still.
2007-02-23 06:52:17 · answer #6 · answered by mad_jim 3 · 0⤊ 1⤋
The speed of light is fixed at 186,000 miles per second and, whatever speed its carrier is doing it is not added to the light speed.
2007-02-23 11:28:01 · answer #7 · answered by Norrie 7 · 0⤊ 0⤋
The speed of light is a constant, what changes is the frequency. It is the frequency that Astronomers use to determine whether a star is moving toward us or away.
2007-02-23 02:42:21 · answer #8 · answered by Anonymous · 2⤊ 0⤋
speed of light is constant i.e. 3*10^8m/s it does not changes whether light travells from a stationary source or from any moving source.
2007-02-23 04:51:49 · answer #9 · answered by rishabh 2 · 0⤊ 0⤋
You cannot alter the speed of light no matterwhat speed you are doing.
The speed of light is 186'000 miles per second.
2007-02-23 06:08:23 · answer #10 · answered by BNP. Protect Great Britain 2 · 0⤊ 0⤋