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4 years ago

The redshift of a star means that _____.

Physics

2 answers:

Mamont248 [21]4 years ago

6 0

The only thing we know of that can red-shift the light of a star is motion away from us.

Gelneren [198K]4 years ago

4 0

The correct answer is D. the star is getting farther away.

When the light has red-shifted, it shows that everything is moving away from a certain point. This is known as the Doppler effect and proves the Big Bang (which would be the center point that everything is moving away from). Just as a 'for your information', blue shift is when the star is moving towards us.

Hope I helped :)

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A wave transfers _____ from the source outward in the direction of wave motion.

DerKrebs [107]

A wave transfers energy from the source outward in the direction of wave motion.

To add, in physics, a wave is an oscillation accompanied by a transfer of energy that travels through a medium (space or mass). Frequency refers to the addition of time.

5 0

3 years ago

A wave pulse travels along a string at a speed of 200 cm/s. What will be the speed if:

34kurt

Answer:

a) $v_f = \sqrt{\frac{2TL}{m}} = \sqrt{2} v = \sqrt{2}2m/s =2.83 m/s$

The velocity increase by a factor of $\sqrt{2}$

b) $v_f = \sqrt{\frac{TL}{4m}} = \frac{1}{2} v = \frac{1}{2} *2m/s =1 m/s$

The velocity decrease by a factor of 2.

c) $v_f = \sqrt{\frac{4TL}{m}} = 2} v = 2 *2m/s =4m/s$

The velocity increase by a factor of 2

d) $v_f = \sqrt{\frac{4TL}{4m}} = v = 2m/s$

The velocity not changes.

Explanation:

For this case we know that the velocity is $v = 200 cm/s = 2m/s$

$v_f$ represent the final velocity after the changes specified,

Part a

The formula for the speed of a wave in a string is given by:

$v = \sqrt{\frac{T}{\rho}}$

And the linear density is defined as:

$\rho = \frac{m}{L}$

And if we replace this we got:

$v = \sqrt{\frac{TL}{m}}$

If the tension mass is doubled we have this:

$v_f = \sqrt{\frac{2TL}{m}} = \sqrt{2} v = \sqrt{2}2m/s =2.83 m/s$

The velocity increase by a factor of $\sqrt{2}$

Part b

If we mass is quadrupled we have this:

$v_f = \sqrt{\frac{TL}{4m}} = \frac{1}{2} v = \frac{1}{2} *2m/s =1 m/s$

The velocity decrease by a factor of 2.

Part c

If the length is quadrupled we have this:

$v_f = \sqrt{\frac{4TL}{m}} = 2} v = 2 *2m/s =4m/s$

The velocity increase by a factor of 2

Part d

For this case we know that the mass and the length are both quadrupled and we got:

$v_f = \sqrt{\frac{4TL}{4m}} = v = 2m/s$

The velocity not changes.

7 0

3 years ago

Which of the following statements is true? The melting and freezing points of a substance are the same. The melting and boiling

insens350 [35]

The melting and freezing points of a substance are the same.

Substances melt and freeze at the same temperature. Hope this helps! :)

4 0

3 years ago

Read 2 more answers

The primary __________ cortex specializes in receiving signals from different parts of the body.

tiny-mole [99]

Answer:

C. somatosensory

Explanation:

The somatosensory cortex is located in the front area of the parietal lobe. It receives signals for various areas of the body registering sensory input.

3 0

3 years ago

Read 2 more answers

The mass and radius of Earth are____ME and____RE, respectively. The mass and radius of the Moon are approximately 186ME and 27RE

oksano4ka [1.4K]

Answer:

1. Mass of the Earth is 5.97219 × 10^24 kg

2. Radius of the Earth is 6,371 km

3. Acceleration due to gravity on the surface of the Earth is 9.81 m/s^2

4. Acceleration due to gravity on the surface of the moon is 1.625 m/s^2

Explanation:

The mass and radius of Earth are 5.97219 × 10^24 kg ME and 6,371 km RE, respectively. The mass and radius of the Moon are approximately 186ME and 27RE, respectively. The acceleration due to gravity on the surface of Earth is 9.81 m/s^2 . The acceleration due to gravity on the surface of the Moon is most nearly 1.625 m/s^2

6 0

3 years ago