5questions for 25 points don't answer the questions if you don't know it. all of the elements, except for hydrogen and helium, originated from the life and death of a a- galaxy b- planet c- moon d- star a main sequence star (such as our sun) is in a state of a- collapse b- equilibrium c- rapid expansion temperature affects a star’s color. the hottest stars appear to be what color? a- red b- yellow c- blue d- pink what determines the life cycle of a star? a- the temperature of the star. b- the luminosity of the star. c- the mass of the star. d- the color of the star. there are billions of stars in the universe. how are they classified? a- by their temperature and luminosity b- by their color and luminosity c- by they size and shape d- by their shape and brightness

1- All of the elements, except for Hydrogen and Helium, originated from the life and death of a Star.

2- A Main Sequence Star (such as our sun) is in a state of equilibrium.

3- Temperature affects a star’s color. The hottest stars appear to be what color?

   Blue

4- What determines the life cycle of a star?  

   The mass of the star.

5- There are billions of stars in the universe. How are they classified?

   by their temperature and luminosity

Explanation:

1) At the beginning of the universe there was only hydrogen and helium, since they were the most simple elements on their structure. Then, stars born from molecular clouds of hydrogen and helium and once they reach the necessary temperature on their core, they start the nucleosynthesis (the fuse of lighter element into heavier elements), for example, hydrogen into helium and helium into berilium.

2) In the stars, there is an equilibrium between two forces, the force of gravity in the inward direction due to their own mass and the radiation pressure in the upward direction as a consequence of the nuclear reaction in their core, that is known as hydrostatic equilibrium.

The radiation pressure is gotten from the nuclear reactions at the core (when lighter elements fuse in heavier elements), but if the nuclear reactions stop, hence, the radiation pressure will also do it and the force of gravity will overcome and break the equilibrium.

Main sequence star is in the state of fuse hydrogen into helium at its core, once the hydrogen is exhausted, the equilibrium breaks since there is not radiation pressure in the upward direction to counteract the force of gravity.

3) Bodies that are hot enough emit light as a consequence of their temperature. For example, an iron bar in contact with fire will start to change colors as the temperature increases, until it gets to a blue color, that is known as Wien's displacement law, which establishes that the peak of emission for the spectrum¹ will be displaced to shorter wavelengths as the temperature increases.

The same scenario described above can be found in the star. A star with high temperature will have a blue color and one with low temperature will have a red color.

4) The evolution of a star is determined exclusively by its mass. For example, a star with more than 8 solar masses will end up its life as a neutron star or a black hole. In the other hand, a star with less of 8 solar masses will end up its life as a planetary nebula or a white dwarf.

5) Stars can be classified by their temperature, since it is easy to determine it by means of their spectrum and Wien's displacement law:

In the other hand, since stars do not have the same size, they have different brightness, since the free mean path of light will be greater in bigger radius.

Key term:

¹Spectrum: decomposition of light on its characteristic colors (wavelengths).

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

elly's long hair:

a. if the salon only takes cash, then this isn't the problem. it doesn't matter how much she has in her checking account.   she can't get a haircut until she has the cash.

b. if she has overdraft protection, then there's no problem.   she can go ahead and write a check that her account can't cover, then sometime later, pay the bank some outrageous usury for loaning her a few bucks for a few days, but with beautiful hair.

c. if elly has some principles, and doesn't want to write a bad check, then now she has a problem.   her desire for the new hairstyle is in conflict with her honesty and integrity.

d.   if the bank will not process a check she writes, then even if she had a million $$ in her account, she couldn't use any of it.   the amount she has in her account is not the problem.   and if i may suggest, she might as well close her checking account, and put the money where it'll work for her.   it's not doing her a bit of good in a checking account, since she can't write any checks.

justin can't pay the full balance:

a. he can't even handle the credit limit he has now.   under no circumstances should he ask for a higher limit.

b.   he can ask for the grace period to be extended.   but that's no solution, the bank will almost certainly refuse anyway, and there are much better options.   he knew the rules of his credit card when he started using it.

c.   he definitely should pay the interest on the balance, plus as much of the balance as he can cover at the same time.

d.   he definitely should pay the minimum otherwise they could shut down his card.   he should also pay as much more as he possibly can.   he should also remember the awkward situation he's in, stop buying stuff on credit that he can't afford, and avoid adding any more debt.

i'd say that justin's best best option isn't on this list of choices.   what he has to do:   pay as much as he can at least the minimum payment plus as much more as he can and then avoid adding more debt.