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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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Which statement best explains why electricity should be conserved?
andrezito [222]
A sounds correct. ....
8 0
3 years ago
Read 2 more answers
De manera individual subraya la respuesta correcta: A) El Método Científico de la física experimental y su búsqueda de respuesta
alexira [117]

Answer:

a. La ciencia.

Explicación:

El método científico de la física experimental y su búsqueda de respuestas tiene un principio básico que es la ciencia. La ciencia es la aplicación del conocimiento del mundo natural y social siguiendo una metodología sistemática basada en evidencias. Sin evidencias no hay aceptación de la observación ni se debe hacer teoría porque la evidencia es el principal criterio para aceptar o rechazar una hipótesis.

6 0
3 years ago
What is the magnitude of the Box's Acceleration?​
mojhsa [17]

The Box's Acceleration : g sin θ

<h3>Further explanation  </h3>

Newton's 2nd law explains that the acceleration produced by the resultant force on an object is proportional and in line with the resultant force and inversely proportional to the mass of the object  

∑F = m. a  

F = force, N  

m = mass = kg  

a = acceleration due to gravity, m / s²  

We plot the forces acting on the block (picture attached) according to the y-axis and the x-axis.

Because the motion of the block is in the same direction as the x-axis, ignoring the friction force with the inclined plane, then

\tt \sum F_x=m.a\\\\W.sin\theta=m.a\\\\mgsin\theta=m.a\\\\a=gsin\thet\theta

4 0
3 years ago
B. Projectile on cliff (range)
dimulka [17.4K]

Answer:

x = 41.28 m

Explanation:

This is a projectile launching exercise, let's find the time it takes to get to the base of the cliff.

Let's start by using trigonometry to find the initial velocity

         cos 25 = v₀ₓ / v₀

         sin 25 = Iv_{oy} / v₀

         v₀ₓ = v₀ cos 25

         v_{oy} = v₀ sin 25

         v₀ₓ = 22 cos 25 = 19.94 m / s

         v_{oy} = 22 sin 25 = 0.0192 m / s

let's use movement on the vertical axis

         y = y₀ + v_{oy} t - ½ g t²

     

when reaching the base of the cliff y = 0 and the initial height is y₀ = 21 m

         0 = 21 + 0.0192 t - ½ 9.81 t²

         4.905 t² - 0.0192 t - 21 = 0

         t² - 0.003914 t - 4.2813 =0

we solve the quadratic equation

        t = \frac{ 0.003914\  \pm \sqrt{0.003914^2 + 4 \ 4.2813 }   }{2}

        t = \frac{0.003914 \ \pm 4.13828}{2}

        t₁ = 2.07 s

        t₂ = -2.067 s

since time must be a positive scalar quantity, the correct result is

        t = 2.07 s

now we can look up the distance traveled

         x = v₀ₓ t

         x = 19.94  2.07

         x = 41.28 m

5 0
3 years ago
A device used to measure the atmospheric pressure is the barometer. true false
Angelina_Jolie [31]
True, I just learned this a week ago. Is this for Chemistry?
3 0
3 years ago
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