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Homework Help: Help Momentum

  1. Nov 12, 2007 #1
    Help!!! Momentum

    A ball, of mass 100g, is dropped from a height of 16m. Its momentum when it strikes the ground is?

    How do you do this calculation?

    Thanks!
     
  2. jcsd
  3. Nov 12, 2007 #2
    What have you tried? Do you know what momentum is?
     
    Last edited: Nov 12, 2007
  4. Nov 12, 2007 #3

    Dick

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    First you compute the velocity. Then you remember the definition of momentum. Get started with the first part.
     
  5. Nov 12, 2007 #4
    Dont' I have to have time to calculate velocity? i know p=mv i just dont know the velocity
     
  6. Nov 12, 2007 #5
    Look in the formulas sticky, at the top of this page. There''s one in there which you can use to solve this.
     
  7. Nov 12, 2007 #6
    i do not see the formula??
     
  8. Nov 12, 2007 #7
    [tex]v^2 = v_0^2 + 2 a \Delta x[/tex]

    [tex]\Delta x[/tex] is the displacement.
     
  9. Nov 12, 2007 #8
    i end up getting 313.6 m/s that can't be right? a= gravity correct?
     
  10. Nov 12, 2007 #9
    You're putting in some formula wrong. Show whet you are doing, and we'll tell you where you messed up.
     
  11. Nov 12, 2007 #10
    0+(2x9.8x16) = 313.6
     
  12. Nov 12, 2007 #11
    Check the formula again.
     
  13. Nov 12, 2007 #12
    grrr im stupid
     
  14. Nov 12, 2007 #13
    Yah A= -9.80 (Or 9.80 down) Thats the gravational force pulling down.
     
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