Why coin drop down into the glass?

In summary, the conversation is discussing why a coin placed on a boardcard will drop down into a glass when the boardcard is hit. The answer is that the force of friction between the coin and the board is not strong enough to overcome the inertia of the coin. This is because objects with mass require a force to move, and the coin has a high level of inertia. The conversation also mentions the age and education level of the person asking the question, as well as the difference between static and kinetic friction. Finally, it is noted that there can be no answer if the question is not understood.
  • #1
Aladin
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0
When we put a coin on a boardcard and both the boardcard and coin put on a glass.
when we hit the boardcard,why the coin drop down into the glass.??
 

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  • #2
what?? I don't understand...
 
  • #3
Are you asking about the inertia of the coin or the surface tension of the water?\
 
  • #4
inertia...it seems to say nothing bout water at all.
 
  • #5
Well the short answer is that the force of friction between the coin and the board is not great enough to overcome the inertia of the coin

I suppose he knew that though...?
 
  • #6
subodei said:
the force of friction between the coin and the board is not great enough to overcome the inertia of the coin

I suppose he knew that though...?
Apparently not, or he wouldn't have asked. We have no idea how old this lad is, or what his level of education is.
The inertial of the coin is very high, and as suodei said, overpowers the forces that hold it to the board. When the board is abruptly removed, the coin stays behind. It's the same principle as the old trick of pulling a tablecloth off while leaving the dishes behind. With a slower movement, the coin would stay with the card.
 
  • #7
Aladin said:
When we put a coin on a boardcard and both the boardcard and coin put on a glass.
when we hit the boardcard,why the coin drop down into the glass.??
As several have noted, the answer relates to the inertia of the coin. All objects that have mass require a force to get them moving (or change their state of motion). The only horizontal force on the coin is the friction between card and coin. If there were no friction, then you could slide the card away at any speed and the coin wouldn't move (until it started falling, of course).

But there is friction. If you move the card slowly, then static friction will move the coin along with the card. But if you move the card quickly, the much lower kinetic friction will be acting: the coin will move, but not as quickly as the card. Now if you move the card real quick, that friction force won't have much time to accelerate the coin; it appears to fall straight down (actually it must move a little to the side as well).
 
  • #8
Doc Al said:
As several have noted, the answer relates to the inertia of the coin.

Of course there is no answer if the question is not understood. :frown:
 
  • #9
Thank you Doc Al my problem is solved by your answer.
 

1. Why does a coin drop down into a glass?

Gravity is the main force responsible for a coin dropping down into a glass. The coin is heavier than air, so it is pulled down by the force of gravity towards the bottom of the glass.

2. What other forces are involved in a coin dropping down into a glass?

In addition to gravity, there may be other forces at play depending on the specific situation. For example, if the glass is filled with liquid, the buoyant force of the liquid may also contribute to the coin's downward movement.

3. Why does a coin sometimes bounce before dropping into a glass?

When a coin is dropped from a height, it may have some initial speed and momentum. If this speed is high enough, the coin may bounce off the surface of the liquid in the glass before eventually sinking down into it. This is due to the conservation of momentum and the elasticity of the coin and the liquid's surface.

4. Can a coin ever float on top of a liquid in a glass?

Yes, it is possible for a coin to float on top of a liquid in a glass. This can happen if the density of the liquid is greater than the density of the coin. In this case, the buoyant force will be greater than the weight of the coin, causing it to float on the surface of the liquid.

5. Is the shape of the glass important in a coin dropping down into it?

The shape of the glass can affect how a coin drops into it. For example, a narrow and tall glass may cause the coin to fall straight down without any bouncing, while a wide and shallow glass may cause the coin to bounce multiple times before finally settling at the bottom. This is due to the different surface areas and volumes of the glasses, which can affect the air resistance and other forces acting on the coin.

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