Question

the existence of dark energy is detected by its gravitational effect on ordinary matter.

• 0 points

true
false
the existence of dark matter is used to explain the acceleration of distant galaxies and expansion of the universe.

• 0 points

true
false

Explanation:

First Question:

Dark energy's existence is inferred from its gravitational - like effect (repulsive gravitational effect in this case) on ordinary matter and the expansion of the universe. So the statement "The existence of dark energy is detected by its gravitational effect on ordinary matter" is True.

Dark energy, not dark matter, is used to explain the acceleration of distant galaxies and the expansion of the universe. Dark matter is mainly used to explain the rotational curves of galaxies and the gravitational lensing effects in galaxy clusters. So the statement "The existence of dark matter is used to explain the acceleration of distant galaxies and expansion of the universe" is False.

Answer:

True

Second Question: