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How Calculate Cat's Jump?

  1. Nov 26, 2011 #1
    Hello Physics Mavens,

    Just watched one of my cats make two upward jumps; both with pinpoint accuracy.

    (Cats are amazing creatures.)

    One height was ~74cm above the floor; the other height ~81cm. He cleared both ledges by ~3cm and softly touched down on his paws at--what seems to be--near zero velocity.

    In addition to being amazed by the accuracy of his internal computer...I wonder how one calculates the force he puts into each jump? Assuming there's a physics formula(s)--would you be so kind as to post an approach/solution?

    CAT's weight: ~0.465kg
    Height of First Ledge*: ~74cm
    Height of Second Ledge*: ~81cm

    *To clarify: He jumped from the floor to the first ledge...jumped back (down) to the floor...then jumped up to the second ledge--in this observation, he did not jump from the first ledge to the second.

    If F = ma = gm; how much 'a' does he exert when leaving the ground such that his 'a' at (near) the desired height (+ ~3cm) approaches zero?

    Also, is there a way to calculate the duration (time) of his jump?

    Many, many thanks in advance.

    Best regards,
    Plane Wryter
     
  2. jcsd
  3. Nov 26, 2011 #2

    Matterwave

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    In order to get a force, you need to know for how long he applies this force. All you can get from the information given is the impulse (with a lot of approximations).

    You can use energy conservation to get the initial velocity he needs to attain to reach the heights required: [itex]\frac{1}{2}mv^2=mgh[/itex]. With this velocity, you know the change in momentum [itex]\Delta p = mv[/itex], and therefore the total impulse [itex]I=F_{tot}\Delta t=\Delta p[/itex]
     
  4. Nov 26, 2011 #3

    A.T.

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  5. Nov 26, 2011 #4
    Your cat only weighs 1 pound? How can a tiny kitten jump that high? My adult cat weighs 11 pounds.
     
  6. Nov 27, 2011 #5
  7. Nov 27, 2011 #6

    A.T.

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