We can use the kinematic equation

where Vf is what we are looking for
Vi is 0 since we start from rest
a is acceleration
and d is the distance
we get
(Vf)^2 = (0)^2 + 2*(2)*(500)
(Vf)^2 = 2000
Vf = about 44.721
or 44.7 m/s [if you are rounding this by significant figures]
That is because it is impossible to create a law for the behavior of every single different gas, so creating laws for an ideal gas helps us understand the basic nature of gasses which might or might not differ slightly or a lot. By understanding how an ideal gas works, we can understand how a normal gas works.
Explanation:
As we know that relation between energy and wavelength is as follows.
E = 
This means that energy is inversely proportional to wavelength. So, more is the energy of an electromagnetic radiation less will be its wavelength.
Also, f = 
Hence, less will be the wavelength more will frequency of a radiation.
Gamma rays are the rays that have highest energy, small wavelength and highest frequency.
Thus, we can conclude that gamma rays are the electromagnetic radiation which has the highest frequency.
Answer:
the second time there is a gas between you and the star,
Explanation:
When you observe the star for the first time you do not have a given between you and the star, therefore you observe the emission spectrum of the same that is formed by lines of different intensity and position that indicate the type and percentage of the atoms that make up the star.
When you observe the same phenomenon for the second time there is a gas between you and the star, this gas absorbs the wavelengths of the star that has the same energies and the atomisms and molecular gas, therefore these lines are not observed by seeing a series of dark bands,
The information obtained from the two spectra is the same, the type of atoms that make up the star