Question

Which of the following is applicable for the Moon's motion around the Earth?

• A. Newton's First Law of Motion
• B. Centripetal Force
• C. Uniform Motion
• D. Newton's Third Law of Motion

Answer 1

Answer: (A), (B), (D)

The correct options are
A Newton's First Law of Motion
B Centripetal Force
D Newton's Third Law of Motion

Newton's First Law of Motion states that an object at rest remains at rest or an object in motion continues to be in motion (without a change in direction or speed) until and unless acted upon by an external force.

The moon, in this case, cannot remain in uniform motion since a centripetal force (centre-seeking force) is acting on it. This force is continuously changing the direction and causing it to move around the Earth. This is not uniform motion.

Also Newton's Third Law of Motion, which states that "To every action there is an equal and opposite reaction", is applicable since both the Earth and the Moon attract each other with the same force but since the mass of the Earth is much larger compared to that of the Moon, the Moon experiences greater acceleration.