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Determining distance(m)

  1. Sep 27, 2006 #1
    The determined Wile E. Coyote is out once more to try to capture the elusive roadrunner. The coyote wears a new pair of Acme power roller skates, which provide a constant horizontal acceleration of 15 m/s2, as shown in Figure P3.73. The coyote starts off at rest 70 m from the edge of a cliff at the instant the roadrunner zips by in the direction of the cliff.

    Figure P3.73
    (a) If the roadrunner moves with constant speed, find the minimum speed the roadrunner must have in order to reach the cliff before the coyote.
    22.9 m/s

    (b) If the cliff is 100 m above the base of a canyon, find where the coyote lands in the canyon. (Assume that his skates are still in operation when he is in "flight" and that his horizontal component of acceleration remains constant at 15 m/s2.)

    I got part a, but I am not getting part b, please help
  2. jcsd
  3. Sep 27, 2006 #2
    yeah Noein I tried it by doing it for each component, but cant get it right
  4. Sep 28, 2006 #3


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    Calculate how long it will take the Coyote to drop through 100m down the cliff. Then use this time to calculate the horizontal distance he will travel during the drop down to the base of the canyon.
  5. Sep 28, 2006 #4
    I am getting it wrong, maybe I set it up wrong?

    squareroot(100/4.9= 4.517 s

    then x= .5(15)(4.517)^2
  6. Sep 28, 2006 #5
    try drawing a picture and writing down what you know. If you are at rest and then start your Vo=0. try filling out a chart of what you know and then looking to see what you need to find, then use the according equation.
  7. Sep 29, 2006 #6


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    Your formula for x do not have the part of his horizontal speed when he left the edge of the cliff. Remember that he accelerated for 70 meters before he got to the edge.
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