Tides are influenced by the force of gravity exerted by the earth, moon and the sun. The sun has a larger mass than the moon and as such has a greater gravitational pull on the earth. the moon however has greater influence over the tides because they are caused by the difference in gravity fields. This means that the moon is the dominant influence due to the fact that the fractional difference in its force across the earth is greater than that seen from the sun.
Frost will disturb the smooth flow of air over the wing, unpleasantly
distressing its lifting competence. In other words, this spoils the even flow
of air over the wings, by this means decreasing lifting capability. Also, frost
may avoid the airplane from becoming flying at normal departure speed.
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>
<span>In order for
an object to accelerate, a <u>force</u> must be applied. It follows Newton’s second
law of motion where it states that a body at rest remains at rest unless a
force is acted upon it. When you move an object, you are exerting a force onto
it. By exerting a force on the object, you are actually displacing it from its
initial position. You cannot apply force to the object without altering its
position. Keep in mind that when you exert work, you are exerting energy too. </span>
