Newton observed that the motion of the moon around the Earth resembled the motion of objects falling towards the Earth’s surface, prompting him to consider whether the Earth’s gravitational force also affects the moon.

The centripetal force continuously pulls objects towards the center of their circular path, preventing them from moving in a straight line and maintaining their circular motion.

In circular motion, the tangent to the circular path represents the direction an object would take in the absence of a centripetal force, moving in a straight line.

Without the centripetal force provided by Earth’s gravity, the moon would pursue a uniform straight-line motion instead of orbiting around the Earth.

The centripetal force for the moon’s orbit around the Earth is provided by the gravitational attraction of the Earth.