What happens when you slowly pulled the cardboard? Explain
What happens when you flicked the cardboard? Explain
What happens when you hit the coin at the bottom? Explain
The Correct Answer and Explanation is:
These questions refer to a classic physics demonstration involving inertia, where a coin is placed on a cardboard resting on top of a glass or cup. The responses to each action differ due to the principles of motion and inertia. Here’s a detailed explanation for each:
1. What happens when you slowly pulled the cardboard?
Answer: The coin moves along with the cardboard.
Explanation:
When you slowly pull the cardboard, friction between the coin and the cardboard causes the coin to move with the cardboard. This is because the coin is not experiencing a large enough unbalanced force to resist the motion caused by the friction. Since you are pulling slowly, there is enough time for the coin to “notice” the change and be dragged along. The force of static friction between the coin and cardboard is strong enough to overcome inertia and initiate movement with the cardboard. This shows that when a force is applied gradually, objects in contact can move together.
2. What happens when you flicked the cardboard?
Answer: The cardboard moves away quickly, and the coin falls straight down into the glass.
Explanation:
This illustrates Newton’s First Law of Motion (the law of inertia), which states that an object at rest stays at rest unless acted upon by an unbalanced force. When the cardboard is flicked quickly, it accelerates rapidly, but the coin tends to remain in its original position because of its inertia. The flick happens so fast that friction does not have enough time to act on the coin to move it sideways. Without enough horizontal force on the coin, it doesn’t follow the cardboard but instead drops vertically due to gravity and lands in the glass. This demonstrates that the coin resists changes in its state of motion.
3. What happens when you hit the coin at the bottom?
Answer: The coin is knocked out, and the rest (cardboard and any item above it) may drop into the glass.
Explanation:
If the coin is at the bottom and you strike it quickly, the sudden force causes it to move while the rest of the setup (like a stack or a card on top) remains mostly unaffected for an instant. This is again due to inertia — the items above are not directly acted upon by the force, so they remain at rest momentarily and may fall straight down. This experiment further confirms how inertia keeps objects in their current state unless an external force acts on them.
Summary:
These scenarios are simple but effective ways to visualize Newton’s First Law of Motion — the principle of inertia. Objects resist changes in motion; if a force is applied slowly, friction may act and move the object with the surface. If the force is quick and abrupt, the object stays in place due to inertia while the surface moves away.