"APPLE FALLS" The story goes that Newton was sitting under an apple tree, an apple fell on his head, and then he suddenly thought of the Universal Law of Gravitation. Though he thought the apple is accelerated, since its velocity changes from zero as it is hanging on the tree and moves toward the ground and by Newton's 2nd Law there must be a force that acts on the apple to cause this acceleration.
"NEWTONS FIRST LAW OF INERTIA" An object that is at rest will stay at rest unless an external force acts upon it and an object that is in motion will stay in motion unless an external force acts upon it.