What does hubble's law tell us?
a) the faster a spiral galaxy's rotation speed, the more luminous it is.
b) the longer the period of a cepheid variable, the greater its luminosity.
c) for every force, there is an equal and opposite reaction force.
d) the more distant a galaxy, the faster it is moving away from us. old, red, and bright and have fewer heavy elements.

Hubble's law tell us that the more distant a galaxy, the faster it is moving away from us. old, red, and bright and have fewer heavy elements.

Option D

Explanation:

Hubble's law explains astronomy that galaxies are moving apart and that their rate of speed is proportional to their distance. This leads to the expanding picture of the universe and by extrapolation back to the Big Bang theory.

The dominant movement occur at the universe causes the gentle expansion called Hubble's Law. The Hubble distance would be the distance between the galaxies and the Earth currently traveling from us in the speed of light, as evidenced by the change in Hubble's law in the equation,

Where,

D- galaxy’s distance (Mpc)

H – Hubble constant (km/sec/Mpc)

V- galaxy’s velocity (km/sec)

While galaxies usually change as expanding smooth, distant stars move faster, and other movements cause mild deviations from the lines provided by Hubble's law.

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