Question

When a blanket is vigarously shaken, the dust falls off. Why?

Answer 1

When we shake the blanket, the dust particles on it want to maintain their inertia of rest, but when the blanket moves,  they do not maintain this inertia and fall down. This is so because of the inertia of rest (static inertia) which is the fundamental property possessed by a body to oppose any change in its state of rest. Or in other words, the body does not want to change its state of rest, but wants to continue its state of rest is called inertia of rest.