Question

Inertia is an object's natural tendency to remain in constant motion or at rest. An object moving through outer space, for example, will continue moving in one direction and at a constant speed due to its inertia, if no other forces act on it. Why do planets constantly change the direction in which they move? A. Most planets do not have any inertia, so their motion constantly changes. B. The force of gravity acts on planets and changes the direction of their motion. C. Each planet's inertia is constantly changing from one moment to the next. D. There are no forces acting on the planets as they move in orbits around the Sun.

Answer 1

Planets constantly change their direction of motion due to the force of gravity acting on them.

Step-by-step explanation:

The planets constantly change the direction in which they move due to the force of gravity acting on them. According to Newton's laws of motion, objects at rest remain at rest and objects in motion continue moving in a straight line at a constant speed, unless acted upon by a force. Since the planets move in elliptical orbits rather than straight lines, the force of gravity is responsible for bending their paths and continuously changing their direction of motion.