1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Give an x-y equation for the path of the particle

  1. Aug 8, 2009 #1
    1. The problem statement, all variables and given/known data
    r(t)=(2sin(wt),3cos(wt))

    a. give unit vector in direction of r'(t)
    b. give unit vector in plane of motion which is normal to r'(t)
    c. give an x-y equation for the path of the particle

    3. The attempt at a solution

    well a. i think is just finding the unit vector but i am having trouble finding it. r'/|r'|=1/root(4w^2cos^2(wt)+9w^2sin^2(wt))*r' i dont think this i right tho because i cant cancel the sin cos squared because of not common factors... and the other 2 i have no idea, please can someone help me.
     
  2. jcsd
  3. Aug 9, 2009 #2
    Re: mechanics

    anyone?
     
  4. Aug 9, 2009 #3
    Re: mechanics

    See the question, it provides you that numbers. You cannot do much about it.

    b) Hint:
    r'(t).normal = 0
    . = dot

    c)
    from r(t)=(2sin(wt),3cos(wt))
    x = 2sin(wt)
    y = 3cos(wt)

    so find h(x) such that y = h(x)
     
  5. Aug 9, 2009 #4
    Re: mechanics

    thanks heaps!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook