Newton concluded that a force from the Earth had to act on the Moon because
A)a force is needed to keep the Moon in motion in its orbit.
B)a force is needed to pull the Moon outward.
C)a force is needed to accelerate the Moon toward Earth away from straight-line motion.
D)the Moon moved at a constant velocity in a straight line.
E)All of the other choices are correct.

Question

Quizplus · Accepted Answer

Newton concluded that a force must act on the Moon to cause it to deviate from straight-line motion and accelerate toward Earth, maintaining its orbit. This is in line with his understanding of motion and the application of his laws, particularly the law of universal gravitation. Choices A and B suggest misconceptions about orbital motion and forces, and D is incorrect because the Moon does not move in a straight line at a constant velocity.

Newton Concluded That a Force from the Earth Had to Act