Answer:
NASA's Chandra X-ray Observatory and other telescopes such as the Hubble telescope.
Explanation:
Dark matter and normal matter have been wrenched apart by the tremendous collision of two large clusters of galaxies.
The above observations have provided the strongest evidence yet that most of the matter in the universe is dark.
Answer:
here we can say that acceleration of the satellite is same as the gravitational field due to Earth at that location
Explanation:
As we know that gravitational field is defined as the force experienced by the satellite per unit of mass
so we will have

now in order to find the acceleration of the satellite we know by Newton's II law

so we will have

so here we can say that acceleration of the satellite is same as the gravitational field due to Earth at that location
Average velocity = (800+1600)/(4+10)
= 171.42m/s