Newton concluded that some force must act on the Moon because ____.
A) a force is needed to pull the Moon away from straight-line motion
B) a force is needed to pull the Moon outward
C) a force is needed to keep the Moon in motion
D) the Moon has at a constant velocity
E) the Moon has a constant acceleration

Question

Quizplus · Accepted Answer

Newton concluded that a force must act on the Moon to pull it away from straight-line motion, in accordance with his understanding of motion and the laws of physics. This is because, according to Newton's first law of motion, an object will remain in its state of motion (either at rest or moving in a straight line at constant velocity) unless acted upon by an external force. The Moon's curved path around the Earth indicates that it is not moving in a straight line, implying the presence of an external force acting on it.

Newton Concluded That Some Force Must Act on the Moon