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B Why does a hammer fall the way it was held when dropped?

  1. Mar 3, 2016 #1

    ProfuselyQuarky

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    I already know that a hammer will drop to the ground on Earth the way it was held, but I don't understand why.
     
  2. jcsd
  3. Mar 3, 2016 #2

    jbriggs444

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    Why would you expect it to do otherwise?
     
  4. Mar 3, 2016 #3

    ProfuselyQuarky

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    Hmmm . . . well, now that I think about, would it by any chance fall the same way that it is dropped because, regardless of mass, everything will fall at the same rate? Since the acceleration due to gravity on Earth is -9.8 m/s^2, the heavy side of the hammer will still drop evenly with the lighter wooden side?

    The explanation I was reading for class was talking all about how "scale falling with an object registers zero" but I don't know what that means.
     
  5. Mar 3, 2016 #4

    phinds

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    Do you think that objects with different weight fall at different rates?
     
  6. Mar 3, 2016 #5

    ProfuselyQuarky

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    They fall in the same rate . . . -9.8 m/s^2
     
  7. Mar 3, 2016 #6

    phinds

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    then see post #2
     
  8. Mar 3, 2016 #7

    ProfuselyQuarky

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    Is this it? What about the "scale falling with an object registers zero" part?
     
  9. Mar 3, 2016 #8

    phinds

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    Have you ever been in an elevator going down?
     
  10. Mar 3, 2016 #9

    ProfuselyQuarky

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    Of course

    EDIT: But an elevator isn't in free fall, is it?
     
  11. Mar 3, 2016 #10

    phinds

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    Post deleted after a PM from the OP.
     
    Last edited: Mar 3, 2016
  12. Mar 3, 2016 #11

    Drakkith

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    That's exactly it.

    It means that since both the scale and the object fall at the same rate, the object isn't applying a force to the scale and thus the scale registers no weight.
     
  13. Mar 3, 2016 #12

    ProfuselyQuarky

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    Thank you! You explained the latter part perfectly.
     
    Last edited: Mar 3, 2016
  14. Mar 5, 2016 #13
    That's a nice explanation. Another one ( if you're familiar with the concept of torque) is that the only force acting on a falling body is gravity. Since this acts on the centre of gravity it creates no torque, so the body wouldn't change its orientation.
     
  15. Mar 6, 2016 #14

    ProfuselyQuarky

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    Wow, I never thought that before! Torque has not yet been covered in my class yet, but I have a brief understanding that it's the measure of the force that causes things to rotate. Torque is NOT a force in of itself, right? Man, I have to look into that for myself, too . . .
     
  16. Mar 7, 2016 #15
    Yes, that's right. Torque is not a force, it's the counterpart of force in rotational dynamics.
     
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