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Homework Help: Measuring height

  1. Sep 21, 2006 #1
    help with part b

    It has been claimed that an insect called the froghopper (Philaenus spumarius) is the best jumper in the animal kingdom. This insect can accelerate at 4400 m/s2 over a distance of 2.0 mm as it straightens its specially designed "jumping legs."

    I got this right

    (a) Assuming a uniform acceleration, what is the velocity of the insect after it has accelerated through this short distance, and how long did it take to reach that velocity?
    velocity 4.19 m/s
    elapsed time .952 ms

    (b) How high would the insect jump if air resistance could be ignored? Note that the actual height obtained is about 0.7 m, so air resistance is important here.

    I dont know what to for part b

    should I plug into the equation v^2= v0^2 + 2ax???

    or what? Its driving me insane
  2. jcsd
  3. Sep 21, 2006 #2
    is the bug jumping verticaly?
  4. Sep 22, 2006 #3


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    Homework Helper

    Once the bug leaves the ground gravity takes over and he will start to delcelarate due to gravitational attraction. That is it cannot accelerate itself any more since it cannot push against the surface. So it will decelerate at a rate of g. Your choice of equation will therefore do just fine. But maybe you should replace the x with a y (joking).
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