Piano & Penny vs Feather Dropped from Empire State Building

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Discussion Overview

The discussion revolves around the physics of objects falling from a height, specifically addressing the claim that a piano and a penny dropped from the Empire State Building would hit the ground at the same time. Participants explore the effects of air resistance and the conditions under which this claim holds true, including the implications of a vacuum environment.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions the validity of the claim that a piano and a penny would hit the ground simultaneously, suggesting that air resistance might affect the outcome, especially with lighter objects like a feather.
  • Another participant asserts that in a vacuum, all objects would fall at the same rate, but acknowledges that air resistance affects the descent in the atmosphere.
  • A different viewpoint suggests that if all air were removed, various objects, including a piano, penny, cup of coffee, and feather, would land simultaneously, but notes that under normal conditions, wind resistance would significantly affect lighter objects.
  • One participant emphasizes that drag affects falling objects, particularly highlighting the feather's higher surface area to mass ratio as a reason for its slower descent.
  • A reference to Apollo 15 is made, where a feather and a hammer were dropped in a vacuum, demonstrating that they fall at the same rate.
  • A participant acknowledges the role of air resistance in the discussion, confirming that the scenario is not in a vacuum.

Areas of Agreement / Disagreement

Participants generally agree that air resistance plays a significant role in the falling rates of objects in the atmosphere. However, there are competing views regarding the specific effects on different objects, particularly lighter ones like feathers, and the implications of a vacuum environment remain a point of exploration.

Contextual Notes

The discussion does not resolve the complexities of how different objects interact with air resistance, nor does it clarify the assumptions regarding the conditions under which the objects are dropped.

tatiana
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I have a serious question, in all seriousness.. So you know how the theory says "if you dropped a piano and a penny off of the empire state buliding they would hit the ground at the same time" Well i was thinking and i wanted to know what would cause this not to be true.. when a coffe cup is empy this does not apply, neithe rif one of these objects were a feather??
 
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If you were in a vacuum, then yes, they would take the same time to hit the ground. But seeing as we're not, air resistance comes into play, slowing the time of descent.
 
If you pumped all the air out of NYC -- which some folks believe to be the case already -- and dropped a piano, penny, cup of coffee, and feather, they would all land at the same time. Under more normal circumstances the wind resistance of each object would need to be taken into consideration so, for instance, the feather might never make it to the ground (at least where you could find it easily).

I'm not sure that the fill-state of the coffee cup would make much difference though.
 
In general, objects dropped in the atmosphere will not hit the ground at the exact same time due to drag. The difference between objects that aren't very light is not usually great enough that you would be able to tell a difference normally however. In a perfect vacuum everything would fall at the same rate since there would not be any drag.
 
As the others said it's the air that slows the feather down. Specifically, it's because the feather has a much higher ratio of surface area to mass.

Apollo 15 famously showed this on the moon (a vacuum), by dropping a feather and a hammer.
http://www.youtube.com/watch?v=5C5_dOEyAfk"
 
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Your all right i forgot that were dealing with air resistance and were not in a vacuum
 

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