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Homework Help: What causes a metal ball to fall faster than a feather on earth?

  1. Jul 19, 2007 #1
    If you drop a metal ball and a feather at the same time the ball will touch the ground before the feather, why is this? What effect is the earth's atmosphere having on the feather? If you dropped a peice of metal in the shape of a feather it still would touch the ground before the feather and if you dropped a peice of metal that weighted the same as a feather the peice of metal would still touch the ground before the feather so what is it? could it be density?
  2. jcsd
  3. Jul 19, 2007 #2


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    All of the above.

    If you dropped a piece of metal that had the same shape and size and weight as a feather, they would fall a the same rate.
  4. Jul 19, 2007 #3


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    feather drops slower because of air resistance too
  5. Jul 19, 2007 #4
    If a metal had the same size and weight as a feather then it would have to be significantly less dense than any other metal right, so is it density.
    I guess its due to the air resistance but as I said if a metal had the same shape as a feather it would still fall faster so why isn't it affected by air resistance(weight), so its probably a conbination of factors.
  6. Jul 19, 2007 #5


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    Thread moved from general technical forums to Homework Help forums.

    Art, welcome to the PF. Please be sure to post homework and coursework questions like this one in the Homework Help forums here on the PF.

    Now to your question -- what effect will the density of an object (given the same wind-resistance shape) have on the maximum velocity that the object can obtain? Use a bicycle with different weight riders going down a hill if you need....
  7. Jul 19, 2007 #6


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    It is. A metal feather experiences exactly the same force due to air resistance as a real feather. And since acceleration due to force is inversely proportional to mass...
  8. Jul 22, 2007 #7

    So if the question was "A brick and a feather fall to earth at their respective terminal velocities. Which object experiences greater force of air friction?"

    does it depend on their actual size? if you had a feather from a sparrow and a regular sized brick is the brick experiences greater force of air friction because it's larger and has to push through more air than the feather? and the brick falls faster because it's mass is so much greater.

    if the feather was from some massive bird and was much larger than the brick, would the feather then be experiencing greater force of air friction then the brick, but probably still be falling slower? assuming the mass of the brick was still greater than the feather.

    - Otis
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