Answer:
b) The star is moving away from us.
Explanation:
If an object moves toward us, the light waves it emits are compressed - the wavelength of the light will be shorter, making the light bluer. On the other hand, if an object moves away from us, the light waves are stretched, making it redder. If from laboratory measurements we know that a specific hydrogen spectral line appears at the wavelength of 121.6 nanometers (nm) and the spectrum of a particular star shows the same hydrogen line appearing at the wavelength of 121.8 nm, we can conclude that the star is moving away from npos, since the wavelength related to that star is more expanded.
Answer:
<em>Well, Your answer will be is </em><em>Work. </em><em>Because, When a spring is compressed, the energy changes from kinetic to potential. This change is caused by work. </em>
<em>Good Luck!~</em>

consider the west direction as positive direction of motion
V' = velocity of airplane relative to observer on ground = 580 mph
v = velocity of wind relative to observer on ground
V = average speed of airplane with no wind = 600 mph
relative velocity is given as
V' = V + v
inserting the values
580 = 600 + v
v = 580 - 600
v = - 20 mph
the negative sign indicates the direction of wind is opposite to direction of airplane , east
hence speed of wind is 20 mph in east direction.
For the gravitational force the formula is P.E. = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m / s2 at the surface of the earth) and h is the height in meters. Notice that gravitational potential energy has the same units as kinetic energy, kg m2 / s2.
A sound wave is a longitudinal wave caused by vibrations and carried through a substance. The particles of the substance, such as air particles, vibrate back and forth along the path that the sound waves travel. Sound is transmitted through the vibrations and collisions of the particles.
This could maybe help you with your answer.