Which force governs the motion of planets, stars, and galaxies?
Show answer & explanation
Correct answer: B
Explanation
Answer: Gravitational force
Explanation: The motion of planets, stars, and galaxies is governed by Gravitational force.
Gravity is the universal attractive force between all objects with mass
It keeps:
planets in orbit around stars
moons in orbit around planets
galaxies bound together
This force was first described mathematically by Isaac Newton’s Law of Universal Gravitation and later refined by Einstein’s General Theory of Relativity.
Additional Key Points:
Gravity is the weakest but most long-range force in nature
It determines: orbital motion, tides on Earth, structure of the universe
The force is proportional to mass and inversely proportional to square of distance:
F=G (m1 m2)/r2
Potential Exam-Oriented Questions & Answers:
Question: Which force keeps Earth in orbit around the Sun?
Answer: Gravitational force
Question: Which is the weakest fundamental force?
Answer: Gravitational force