Question

Why does a coin placed on a card, drop into the tumbler when the card is rapidly flicked with the finger?

Answer 1

A momentary force acts on the card when it is flicked with fingers which causes it to move away. But the coin placed on it is bot does not share the motion at once and continues to stay at rest which is attributed to inertia of rest. Eventually, the coin falls down into the tumbler due to the gravitational pull.