Question on speed of light and sound?( Please read the details before answering the question)?

Question

'speed of light/sound(flash/beep) does not depends on the speed of the
source'.
Does a continous flow of light depends on the speed of the source?

for light waves
When a photon has high frequency it has lower wavelength. Does that means
that the velocity of light waves never changes with different frequencies or
wavelengths?

for sound waves
what about doppler effect?

Answer 1

You are absolutely right. The speed of light, c, is constant (in a near-perfect vacuum like outer space). Also the speed of sound in air is constant (at sea level). Think of a long, straight conveyor belt traveling at a constant speed, say 10 feet per second. Your job is to place cans on the belt at the rate of one per second. If you stand still the cans will reach the other end of the belt at the ratte of one can per second. If you walk in the direction of the belt the cans will be closer together. If you walk in the opposite direction of the belt the cans will be farther apart. Thus, in air a train whistle moving toward you places vibration peaks in the air closer together than if the train was stationary (raising the pitch you hear). As the train moves past you, it places vibration peaks farther apart (lowering the pitch you hear). Although the actual pitch of the whistle was constant the motion of the train relative to your ears acted like a conveyor belt.

The same goes for light. If a distant star is moving away from us, the peaks of the light's waveform are stretched out (lowering the frequency we see). A blue star looks slightly redder, called a red shift. An approaching star exhibits a blue shift. In either case the apparent shift in frequency of sound or light is known as the Doppler effect.

Answer 2

Some provable facts about the speed of light:
- The speed of light is only constant in a vacuum (it can be much slower when passing through material, like glass).
- The speed of light is independent of the frequency of the light.
[Proof: Stars would appear to be multicolored trails rather than points of white light if this was not true].
- The speed of light is independent of the speed of the source.
[Proof:
A supernova is an exploding star.
As the material of the star is "burning" it emits light.
The velocity of the material at the edge of the explosion is much higher (i.e. it's moving faster) than the material at the center of the star.
If the speed of light depended on the speed of the source, then the light emitted from the material in the center of the explosion (moving slowly) would take much longer to get to Earth than the light emitted at the edge of the explosion (moving very fast).
Because the star is very far away, the difference in speeds would be very noticeable.
This would mean that the supernova would appear to take several years to happen.
In fact, supernovas appear to take only a few days.
The only way for this to be possible is if the light emitted at the center of the explosion was traveling at the same speed as the light at the edge of the explosion.
]
- What does change when the source is moving is the frequency of the light. This is called "red-shift" (or "blue-shift" if the source is traveling towards you).

For sound waves:
- The sound travels through the air. [Proof: There is no sound in a vacuum.]
- The speed of sound is independent of the frequency of the sound.
[Proof: When you go to a concert, and sit far away from the sound system, the music sounds the same (but quieter) than when you are sitting next to the sound system. If the speed of sound was based on the frequency of the sound, then different frequencies would reach your ear at different times and the music would sound distorted.]
- The frequency of the sound depends on the relative velocity of the source. This is the Doppler effect. [Proof: listen to the sound of a scooter passing by.]

Answer 3

Both light speed and the speed of sound will remain same weather the source move or not But the frequency will change. The light will red shift when moving away. The frequency will be lowered than the emitted frequency. Same with sound also. When the object is moving towards you the light will blue ****. That is the frequency will increase the same with sound as well. However the speed of sound depends upon the medium it travels.
The red shift and blue shift is the Doppler's effect.

Answer 4

The speed and the frequency of the sound also depend on the speed of the medium in which they travel. The speed of sound in air is 761MPH. With respect to the ground, sound will travel 861MPH in the direction of a 100MPH wind but 661MPH in the opposite direction.

To what extent is that true of light? I don't think I've ever seen that question asked! Food for thought ...

Answer 5

light always stays the same speed.

look up the theory of relativity thats based around my answer.

Answer 6

sorry I could not