Answer:
a.After 
second Mr Comer's speed 
b.Distance travelled by Mr.Comer in seconds 
Explanation:
a. Lets recall our first equation of motion 
Now we know that 
, 
and
Plugging the values we have.
Then Mr.Comer's speed after sec 
b.
Lets find the distance and recall our third equation of motion.
So 
distance covered.
Dividing both sides with 2a we have.
Plugging the values.
So Mr.Comer will travel a distance of .
It has to due with numbers so I would say the last one!
Answer:
red shift, indicating that the universe is expanding
Explanation:
Doppler effect occurs when a source of a wave (e.g. light, or sound waves) moves relative to an observer; as a result of this relative motion, the wavelength of the wave appears lengthened/shortened to the observer. Two situations can occur:
- The source of the wave is moving towards the observer - in this case, the wavelength of the wave becomes shorter. If the wave is visible light, such as the light emitted by distant galaxies, this means that the wavelength of the light shifts towards the blue-end of the spectrum (blue-shift)
- The source of the wave is moving away from the observer - in this case, the wavelength of the wave becomes longer. If the wave is visible light, such as the light emitted by distant galaxies, this means that the wavelength of the light shifts towards the red-end of the spectrum (red-shift)
In our universe, we observe a red-shift for all the distant galaxies: this means that these galaxies are moving away from us, so this is an indication that the universe is expanding.
