Question

Which of the following show(s) the importance of the universal law of gravitation?

• A. The force that is responsible for binding us to the Earth.
• B. The motion of the Moon around the Earth.
• C. The motion of planets around the Sun.
• D. When you fire a bullet, the gun recoils backward and the bullet is moving forward

Answer 1

Answer: (A), (B), (C)

The correct options are
A The force that is responsible for binding us to the Earth.
B The motion of the Moon around the Earth.
C The motion of planets around the Sun.

Newton's law of universal gravitation states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
The universal law of gravitation is important because it tells us about:

$\to$ The force that is responsible for binding us to the earth.
$\to$ The motion of the moon around the earth.
$\to$ The motion of planets around the sun.
The recoil of gun when the bullet is fired is the consequence of Newtons's third law i.e. every action has an equal and opposite reaction.