Question

if you shake the branches of tree,the fruits fall down. why?

Answer 1

When fruits ripen, they tend to loosen the bonding with the branch, when we shake the same, it falls due to the gravity pull.

Answer 2

Due to inertia of rest.

When we shake a tree, the fruit which was at rest tries to stay at rest but the branches come to motion. The branch moves to a different position whereas the fruit tries to stay at the same position which leads to detachment of the fruit from the branch. Due to gravity, the detached fruit falls down.