Which statement explains how planets move in orbit as supported by Newton’s first law of motion?

Question

Planets can change the direction of their own orbital path.
Planets can change orbits due to their inertia.
Planets in motion will have a constant speed unless acted on by an outside force.
Planets with a greater mass will orbit more quickly than smaller planets.

Answer 1

The statement that best explains how planets move in orbit as supported by Newton’s first law of motion is:

"Planets in motion will have a constant speed unless acted on by an outside force."

Newton's first law of motion, also known as the law of inertia, states that an object in motion will stay in motion at a constant velocity unless acted upon by a net external force. This principle is applicable to the motion of planets in their orbits, as they continue to move at a constant speed in a curved path around the sun unless influenced by gravitational forces or other external factors.