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irakobra [83]
3 years ago
12

A blue shift in light from a star indicates what?

Physics
1 answer:
blagie [28]3 years ago
5 0
We don't know.  The only way we have to explain it is as the result of
a "Doppler effect", that is, by assuming that the star is approaching us. 

But if the Doppler effect is really at work in the cosmos, then the vast
majority of galaxies, along with all of their stars, are receding from us ...
as if space itself and the entire universe were expanding ! 

That's the current assumption, because no other plausible cause
has been found for the shift of spectra from distant objects.  But
nothing in science is ever settled, and the search goes on.
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Two Earth satellites, A and B, each of mass m, are to be launched into circular orbits about Earth’s center. Satellite A is to o
Vera_Pavlovna [14]

Answer:

Explanation:

Orbital radius of satellite A , Ra = 6370 + 6370 = 12740 km

Orbital radius of satellite B , Rb = 6370 + 19110 = 25480 km

Orbital potential energy of a satellite = - GMm / r where G is gravitational constant , M is mass of the earth and m is mass of the satellite

Orbital potential energy of a satellite A = - GMm / Ra

Orbital potential energy of a satellite B = - GMm / Rb

PE of satellite B /PE of satellite A

=  Ra / Rb

= 12740 / 25480

= 1 / 2

b ) Kinetic energy of a satellite is half the potential energy with positive value , so ratio of their kinetic energy will also be same

KE of satellite B /KE of satellite A

= 1 / 2

c ) Total energy will be as follows

Total energy = - PE + KE

- P E + PE/2

= - PE /2

Total energy of satellite B / Total energy of A

= 1 / 2

Satellite B will have greater total energy because its negative value is less.

5 0
3 years ago
Which of the following best describes the use of a renewable resource? (2 points) Most power plants burn fossil fuels to generat
kolbaska11 [484]

Which of the following best describes the use of a renewable resource?

Answer:

There are areas in California that use the heat from deep in the Earth to generate electricity.

Explanation:

It comes from the earth itself and we use a lot of things that comes from the earth and deep within it.

5 0
3 years ago
What is it called when a reading is converted into computer language? computerizing surveying digitizing converting
disa [49]
Digitizing is the correct answer
3 0
3 years ago
A strong man and a weak man are trying to carry a ladder . How should they carry it in such a way that the weak person feels les
dsp73

Answer:

The strong person should carry the ladder at the  front end and the weak person should carry it at the back end.

Explanation:

this is because in such a case the strong person has to pull the ladder whereas the weak person at the back end have to push the ladder. In such case it is easier to push because the weak person can use the force of gravity of his own body for pushing the ladde.

However in case of pulling the ladder one has to overcome his own gravity to pull the heavy object

<u>                                                                                                                                 </u>

<h2><em>I Hope it help you </em></h2>
7 0
3 years ago
Read 2 more answers
How does the voltage applied to the electric motor affect the coil's number of rotations and its rotational direction
sleet_krkn [62]
Higher voltage means faster rotation.  Changing the voltage polarity changes the direction of the motor.
3 0
3 years ago
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