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Homework Help: Force vs. time

  1. Apr 29, 2007 #1
    A projectile is fired with speed v at an angle with respect to the horizontal. Assume no air resistance. The projectile returns to the same level and it has a range R and altitude H.

    Whats the impulsive force in the case of the projectile? what does the F vs. t for the projectile look like?
    Last edited: Apr 30, 2007
  2. jcsd
  3. Apr 29, 2007 #2
    Can you be more specific? If you just mean an object in the air here on Earth, neglecting wind resistance, the force is always the same; gravity pulls down. Constantly. So... is the answer you want just "a flat line"? Surely you wanted more than that.
  4. Apr 30, 2007 #3
    Typically impulses are used with inelastic collisions, such as a projectile hitting another object and indenting it somewhat. For example, imagine dropping a golf ball into a bowl of sand.

    Please be more specific as to which forces you are trying to calculate. If it is a homework problem, post the whole question.
  5. May 1, 2007 #4


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    Assuming a flat earth here (R small compared to earth's radius). Speed v, and angle of initial launch can be determined from maximumum height H and range R.

    The force depends on how long it takes to go from speed 0 to speed v and the mass of the projectile. The simplest case would be an idealistic constant force "cannon".
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