Table of Contents

- 1 What happen when the source is far away from the observer?
- 2 What happens to a wave when a source is moving away from an observer?
- 3 Does the speed of light change if the source is moving?
- 4 What happens to light waves as they move away from their source?
- 5 What happens if an object is moving away from US?

## What happen when the source is far away from the observer?

We can say that if the observer is moving towards the source, its velocity is positive, or greater than zero, while if it is moving away from the source, its velocity is negative, or less than zero. If you put a negative number for Vo into the formula above, the result will be that the frequency decreases.

**What happens to the amount of light coming from a source as it moves away from you?**

When the source moves away from you and the wavelength gets longer, we call the change in colors a redshift. Because the Doppler effect was first used with visible light in astronomy, the terms “blueshift” and “redshift” became well established.

**What occurs when the light source is moving away from the observer or when the space between the observer and the source is stretched?**

Redshift occurs when the light source is moving away from the observer or when the space between the observer and the source is stretched.

### What happens to a wave when a source is moving away from an observer?

Since the time between waves is reduced, the frequency is increased. Similarly, if the sound source is moving away from the observer, the frequency (and therefore pitch) is decreased.

**Why does the Doppler effect occur when an observer is moving?**

If the observer moves toward the source at a speed vo, more waves are intercepted per second and the frequency received by the observer goes up. Effectively, the observer’s motion shifts the speed at which the waves are received; it’s basically a relative velocity problem.

**When a light source is moving towards the observer so frequency increases then the shift is known a?**

The Doppler effect describes the change in the observed frequency of a wave when there is relative motion between the wave source and the observer. It was first proposed in 1842 by Austrian mathematician and physicist Christian Johann Doppler.

## Does the speed of light change if the source is moving?

Light in Motion The Special Theory of Relativity is based on Einstein’s recognition that the speed of light does not change even when the source of the light moves.

**In which case is the Doppler effect strongest?**

The maximum Doppler shift is obtained when θ = 0, whereas in imaging the strongest echoes occur when θ = 90º.

**Does Doppler effect depend on distance?**

Yes, the Doppler effect depends on the distance. The sound frequency is higher when the distance is closer between the observer and the source and the frequency becomes lower as the distance between the observer and the source is higher.

### What happens to light waves as they move away from their source?

The same thing can happen to light waves. While light is always moving away from its source at the same speed, if your source is moving at a significant fraction of the speed of light relative to whoever’s watching, the wavelength (or color) of the light will change dramatically. Let’s use your example: 50% of the speed of light.

**What happens when a source moves away from an observer?**

Source moving away from observer: Notice that in both cases, moving observer and moving source, if the source and observer are moving together, the frequency goes up. If they are moving apart, the frequency goes down. However, the amount that the frequency change depends on whether it is the source or the observer that is moving.

**What happens when light is moving at a fraction of the speed of light?**

While light is always moving away from its source at the same speed, if your source is moving at a significant fraction of the speed of light relative to whoever’s watching, the wavelength (or color) of the light will change dramatically. Let’s use your example: 50% of the speed of light.

## What happens if an object is moving away from US?

“ If an object is moving away from us at half the speed of light and shining a light back at us, is the light that hits us going half the speed of light relative to us? ” A source of light waves moving to the right, relative to observers, with velocity 0.7c. The frequency is higher for observers on the right, and lower for observers on the left.