Answer:
1). 
2). Toward us
3). 
4). Toward us
5). 
6). Away from us
7). 
8). Away from us
Explanation:
Spectral lines will be shifted to the blue part of the spectrum if the source of the observed light is moving toward the observer, or to the red part of the spectrum when it is moving away from the observer (that is known as the Doppler effect).
The wavelength at rest is 121.6 nm (
)

Then, for this particular case it is gotten:
Star 1: 
Star 2:
Star 3:
Star 4:
Star 1:
Toward us
Star 2:
Toward us
Star 3:

Away from us
Star 4:

Away from us
Due to that shift the velocity of the star can be determine by means of Doppler velocity.
(1)
Where
is the wavelength shift,
is the wavelength at rest, v is the velocity of the source and c is the speed of light.
(2)
<em>Case for star 1
:</em>
<em></em>
Notice that the negative velocity means that is approaching to the observer.
<em>Case for star 2
:</em>
<em>Case for star 3
:</em>
<em>Case for star 4
:</em>
I don’t see any answer choice but the best way is asking questions about the natural phenomenon, making hypothesis, and predicting the consequences in the hypothesis.
There are 4 in there I believe
A slit of width 0.01 mm has light of wavelength 600 nm passing through it onto a screen 60 cm away. The central maximum will be 7.2 cm .
The central maximum is the brightest central portion of the diffraction pattern. The central maximum is the widest and has the maximum intensity.
The diffraction pattern involves a central bright fringe, also known as the central maxima. Furthermore, central maxima is surrounded by dark and bright lines known as the secondary minima and maxima.
Given
slit width = 0.01 mm = .01 *
m
wavelength = 600 nm = 600 *
m
distance from screen = 60 cm = 60 *
m
width of central maxima = (2 * lambda * D) / d
= 2 * 600 *
* 60 *
/ .01 *
= 7.2 *
m
To learn more about central maxima here
brainly.com/question/14279157
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