Question

explain why some of the leaves may get detached from a tree if we vigorously shake its branch

Answer 1

due to inertia of rest the leaves didn't move until and unless an external force was applied .
So after applying the force , the gets displaced and gets detached from the tree .

Answer 2

Explanation:

The answer of this cause lies behind the Newton’s First Law of Motion. Initially, leaves and tree both are in rest. But when the tree is shaken vigorously, tree comes in motion while leaves have tendency to be in rest. Thus, because of remaining in the position of rest some of the leaves may get detached from a tree if we vigorously shake its branch.