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trapecia [35]
3 years ago
12

Why does the presence of redshift in spectra of galaxies support an understanding of an expanding universe?

Physics
1 answer:
xenn [34]3 years ago
7 0

Explanation:

Doppler's Effect: If a source is moving towards the observer the frequency of the waves emitted by the source will increase( wavelength will decrease). If the source is moving away from the observer the frequency of the waves emitted by the source will decrease( wavelength will increase). The best example of this is the changing frequency of siren of an ambulance as it moves towards us and then away from us.

The same phenomenon can be observed in celestial objects. When the object will move towards us the wavelength will decrease thus the spectrum will be shifted towards the blue part. This is known as blue shift.

If the object moves away from us the wavelength will increase and thus the spectrum will be shifted towards red part. This is know as Red-shift. This is because red has longer wavelength (620 - 750nm) than blue (450-495nm)

Thus if a galaxy shows us red-shifted spectra it means that it is moving away from us. we have observed this phenomenon in various galaxies thus supporting the expanding universe theory.

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If the resistance of a circuit increases, that means that the current has to
Gnoma [55]

Answer:

If resistance increases current decreases.

Explanation:

  • Current is <em>inversely proportional</em> to the resistance.
  • from the relation given below, we can clearly see the relation between current and resistance;

                              V=IR

                              I ∝ 1/R

This relation shows that when resistance increases,current decreases.

4 0
3 years ago
What must happen to an atom of magnesium in order to become a magnesium ion
Zielflug [23.3K]
I would assume that the magnesium would have to come into contact with an ion in order to become a magnesium ion. 
6 0
3 years ago
Each second, 1250 m3 of water passes over a waterfall 150 m high. Three-fourths of the kinetic energy gained by the water in fal
mote1985 [20]

Answer:

The generator produces electrical energy at a rate of 1378125000 J per second.

Explanation:

volume of water falling each second is 1250 m^{3}

height through which it falls, h is 150 m

mass of 1 m^{3} of water is 1000 kg

⇒mass of 1250 m^{3} of water, m = 1250×1000 = 1250000 kg

acceleration due to gravity, g = 9.8 \frac{m}{sec^{2} }

in falling through 150 m in each second, by Work-Energy Theorem:

Kinetic Energy(KE) gained by it = Potential Energy(PE) lost by it

⇒KE = mgh

        = 1250000×9.8×150 J

        = 1837500000 J

Electrical Energy = \frac{3}{4}(KE)

                            = \frac{3}{4}×1837500000

                            = <u>1378125000 J per second</u>

8 0
3 years ago
With respect to the earth, object 1 is moving at speed 0.80 c to the right. Object 2 is moving in the same direction at speed 0.
viktelen [127]

Answer:

0.976 c

Explanation:

v_{1e} = velocity of object 1 relative to earth = 0.80 c

v_{21} = velocity of object 2 relative to object 1 = 0.80 c

v_{2e} = velocity of object 2 relative to earth

Velocity of object 2 relative to earth is given as

v_{2e}= \frac{v_{1e} + v_{21}}{1 + \frac{v_{1e}v_{21}}{c^{2}}}

v_{2e}= \frac{0.80 c + 0.80 c}{1 + \frac{(0.80c)(0.80c)}{c^{2}}}

v_{2e} = 0.976 c

6 0
3 years ago
make a list of different types of energy sources found in our surroundings and categorize them into different form of energy.​
MrRa [10]

Answer:

hdcygcyh

Explanation:

8 0
3 years ago
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