Hi there!

According to Newton's Second Law, force is calculated with the formula:
F = m × a, where:
F = force (N)
m = mass (kg)
a = acceleration (m/s²)
Gravity causes the motions of planets, stars, and galaxies. It's why the Moon orbits around the Earth, and the Earth orbits around the Sun, and the solar system orbits around the galaxy.
Answer:
Explanation:

Subtract both sides by
:

Divide both sides by -2*a:

Add both sides by
:

Subtract both sides by
:

The universe is made up of baryonic matter.(neutrons,electrons,protons)