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Homework Help: Big physics question (really )

  1. Apr 13, 2008 #1
    Big physics question (really urgent)

    http://img135.imageshack.us/img135/6500/physicsdt8.jpg [Broken]

    I solved a,b, need help with the rest, how do u get velocity ??

    Please help. This needs to be submitted soon
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Apr 13, 2008 #2
    This question is very vague.
    It says that the object is moving at a constant velocity of 5.6m/s.
    First of all it does not specify what kind of velocity; Angular or Tangential?
    Lets assume tangential...

    The question ask what the objects velocity is, yet it already gave the CONSTANT velocity as 5.6m/s. The only change the question states that the object makes is an angular displacement of 9.5rad, which brings no reason for a change in velocity unless the specific time is given, which it is not, so one would assume that the tangential velocity remains constant as the question previously stated. And if this is true than the object would experience no acceleration at all so that question does not appear valid. However if it is asking for the Angular speed after a dis. of 9.5rad then:

    9.5rad = 34.2m
    5.6m = 1s
    34.2m = 6.107s
    9.5rad= 6.107s
    w = 9.5rad/6.107s = 1.56 rad/s

    However acceleration is still nonexistent.

    Then it ask for the total force exerted on the object, again not specifying what kind of force. Lets again assume it means Centripetal force. If 5.6m/s is referring to tangential acc. then we find:

    Fc = (Vt^2)/r
    Fc = 5.6^2/3.6= 8.71 N
  4. Apr 14, 2008 #3
    for the angle you can convert it to degrees by multiplying it by 180/pi then take the sin of that and multiply it by 3.6 to find position vector j.

    for velocity it should be the original velocity

    for acceleration it is centripetal acceleration

    for force it is centripetal acceleration multiplied by mass
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