Question

Leaf of a tree may get detached if we vigorously Shake It brunches why

Answer 1

Because of inertia of rest. While shaking the stem may get into motion but the leaves, due to inertia of rest, stay where they are and get detached.

Answer 2

some leaves of tree may get detached from a tree if we vigorously shake its branch due to inertia of rest leaves are in the state of rest with respect to the tree so they possess inertia of rest .