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3 years ago

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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4. How does a molecule differ from an atom

tia_tia [17]

Answer:

Explanation:

In a molecule, atoms are bonded together by single, double, or triple bonds. An atom has a nucleus surrounded by electrons. ... So another difference between atoms and molecules is that when similar atoms combine together in varying numbers, molecules of different properties can be formed.

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3 years ago

Read 2 more answers

What term describes the resistance that one encounters when moving over another

Anvisha [2.4K]

Friction? For example, like when a car's tires skid on rough concrete.

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2 years ago

The drum of a washing machine spins at 200 rpm the drum had a radius of 0.5m what will the centripetal force experienced by a to

miskamm [114]

The centripetal force experienced by the towel is 55 N.

The given parameters;

angular speed of the washing machine, ω = 200 rpm
radius of the machine' drum, r = 0.5 m
mass of the towel, m = 0.25 kg

The centripetal force experienced by the towel spinning along the walls of the drum is calculated as follows;

Fc = mrω²

where;

Fc is the centripetal force

ω is angular speed in rad/s

The angular speed in rad/s is calculate as;

$\omega = \frac{200 \ rev}{\min} \times \frac{2\pi \ rad}{1 \ rev} \times \frac{1\min}{60 \ s} \\\\\omega = 20.95 \ rad/s$

The centripetal force experienced by the towel is calculated as;

$F_c = mr\omega ^2\\\\F_c = 0.25 \times 0.5 \times (20.95)^2\\\\F_c = 54.9 \ N \ \approx 55 \ N$

Thus, the centripetal force experienced by the towel is 55 N.

Learn more here: brainly.com/question/20905151

5 0

2 years ago

A 10 kg bear is running to the right at 10 m/s. He crashes into another 10 kg bear running to the left at -5 m/s. They collide a

faust18 [17]

Answer:

Total momentum is conserved

Explanation:

Conservation of Momentum

The momentum is a physical magnitude that measures the product of the object's velocity by its mass. The total momentum of a system is the sum of all its components' individual momentums. The two-bear system starts with a total moment of

$p=m_1v_1+m_2v_2=(10)(10)+(10)(-50)=50\ kg.m/s$

When both bears stick together, the total mass is 20 kg, and the new momentum is

$p'=(20)(2.5)=50 \ kg.m/s$

We have assumed both bears move to the right after the collision. In this situation, the total momentum is conserved

7 0

3 years ago

When conducting an investigation outside, you can assume it is safe to touch my plant or animal you see.

noname [10]

False, all scene are combed for clues and photographed.

4 0

3 years ago