Discover Why a Penny Falls into a Glass When Pushing a Card - Explained

[smhaq]

My question is that if i had put a penny over a piece of a card paper placed on a glass(empty).then i pushed a card with a sudden stroke of finger,card moved ahead while the coin falls in a glass.Why it does so?

 

[catkin]

The only force acting on the penny is caused by friction between penny and card. Try pushing the penny along the card by the edge to get a feel for now much that is. Because of the high speed your sudden stroke of finger gives to the card, this friction force only acts for a short time.

Intuitively you are expecting the penny to move sideways with the card. The penny starts at rest; for the penny to move sideways it has to be accelerated. The small friction force and short time that the small friction force is applied to the penny mean the penny is accelerated very little.

The penny is accelerated so little that it appears to to stay where it is, dropping straight into the glass. Watch carefully from the side and you will see the penny does move slightly in the directon of the card.

It may be that the penny is in poor contact with the card; it might be slightly flicked up by shock waves in the card from your your sudden stroke of finger; air may be dragged into the gap between penny and card. Both these effects would reduce the friction resulting in even less acceleration.

 

[ogb p]

I would explain this phenomenon using the principles of physics. When the card is pushed with a sudden stroke of the finger, it creates a force that is greater than the force of gravity acting on the penny. This force causes the card to move forward, while the penny, being lighter, falls into the glass due to the force of gravity.

Additionally, the shape and size of the penny and the glass also play a role in this experiment. The penny is round and smaller in diameter than the glass, so it can easily fit through the opening and fall into the glass. The glass, on the other hand, is larger and wider, providing enough space for the penny to fall through.

Another factor to consider is air resistance. When the card is pushed, it creates a disturbance in the air around it, which exerts a force on the penny. This force, combined with the force of gravity, causes the penny to accelerate and fall into the glass.

Overall, the combination of these forces and the physical properties of the objects involved in this experiment result in the penny falling into the glass when the card is pushed. This can be further explored and tested by varying the size and weight of the objects, as well as the force used to push the card.