Which word describes how the planets are held in Earth's solar system together?
A. A tidal force
B. Friction
C. Gravity
D. An atomic force
C. Gravity
The word that describes how the planets are held in Earth's solar system together is C. Gravity.
The correct answer is C. Gravity.
To understand why gravity is the force that holds planets in Earth's solar system together, we need to know a bit about gravity and how it operates in the universe.
Gravity is a fundamental force of nature that exists between any two objects that have mass. It is a force of attraction that pulls objects towards each other. In the case of the planets in Earth's solar system, their mutual gravitational attraction keeps them in their orbits around the Sun.
The Sun is the most massive object in our solar system, and its gravitational pull is what keeps all the planets in orbit around it. The force of gravity emanating from the Sun pulls the planets towards it, causing them to continuously move in curved paths around it.
This gravitational force acts as a centripetal force, preventing the planets from flying off into space or collapsing into the Sun. The balance between the gravitational force and the forward momentum of the planets keeps them in stable, elliptical orbits.
Therefore, the correct answer is C. Gravity, as it is the force that holds the planets in Earth's solar system together.