Answer:
56km
Explanation:
168 ÷ 240 = 0.7
0.7 × 80 = 56km
240 is the amount of minutes in 4 hours.
We divided 168 by 240 to get the distance covered in 1 minute. Afterwards, we needed 80 minutes so we multiplied the answer by 80.
The law of energy conservation states that energy cannot be created or destroyed, so choices B to D are immediately invalid. Choice A can explain this occurrence: <u>A. Some of the energy is used to combat friction, and thus is transformed from mechanical energy to heat.</u>
The lion covered 5 miles in 0.2 hours. With a quick division you can find the speed per hour: 5 / 0.2 = 25 mi/h
Answer:
That the universe (the balloon for this case) is expanding and that is the reason why the galaxies (the dots) appear to move away one from another.
Explanation:
By means of looking at the spectra of galaxies, it can confirm that they are moving away in an accelerated motion.
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 source in this particular case is represented for each of the galaxies.
Hence, the redshift represents this shift of the spectral lines to red part in the spectrum of a galaxy or any object which is moving away. That is a direct confirmation of how the universe is in an expanding accelerated motion.
The redshift can be define in analitic way by trought the 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)
Where z is the redshift.
The ballon example, once that it is inflating, represents how is the universe which it is expanding and that is the reason why the galaxies (the dots) appear to move away one from another.