Hello there. I've decided this to be a long thread because I will ask many many things and I hope to discuss many things here.

If a coin is placed on a piece of card resting atop of a jar, it is possible to flick the card away sharply so that the coin falls into the jar. Explain why this is so.

Now my assumption is Newtons first law and smoothness of the card. The force exterted on the card to make it move is not in straight line acting on the coin. Newtons pair laws states that both forces muct act from two different object, same magnitude AND direction - so they have to act along the same route as well.

Considering the penny is atop the card, it is not receiving the force no?

The coin falls because the friction between the coin and the card is not a large enough force to move the coin before the card is past and it falls. If the card had much higher friction then this would not be the case.

The coin falls because the friction between the coin and the card is not a large enough force to move the coin before the card is past and it falls. If the card had much higher friction then this would not be the case.

Just what I thought. But I was also wondering if it was something to do with the magnitude and direction of the force applied