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!

Mechinical vibration - simple

  1. Feb 22, 2009 #1
    so u = -cos(t) + sqrt(3)sin(t)

    so the Wo = 1, and R =2, but how do i find delta?

    tan(del) = sqrt(3)/-1, but the answer has it as

    u = 2cos(t-2pi/3)

    i can't get the 2pi/3 no matter what i do...

    thanks
     
  2. jcsd
  3. Feb 22, 2009 #2
    If you follow the posting guidelines I think it will be easier for someone to answer you. The question doesn't seem to be very clear.
     
  4. Feb 22, 2009 #3
    acutally, i found my mistake!
     
  5. Feb 22, 2009 #4
    um one more question, what should be the unit for metric?

    should i do it in kg, m, seconds, always?

    thanks
     
  6. Feb 22, 2009 #5
    yeah always use SI units
     
  7. Feb 22, 2009 #6
    haha

    ok, ONE LAST QUESTION (of this thread)..

    how do i know when it's "weight" or "mass"? is it in the wordings of the problem?

    thanks
     
  8. Feb 22, 2009 #7
    Weight is a vector, a force. You can see that the dimensions of a force would be kg m/s^2 or Newtons. Mass is a scalar quantity and will be measured, if in SI units, in kg only.

    F=MA

    Weight = mg

    where m is mass and g is the acceleration due to gravity
     
  9. Feb 22, 2009 #8

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




Similar Discussions: Mechinical vibration - simple
  1. Vibrating spring (Replies: 1)

  2. Transverse vibrations (Replies: 6)

  3. Resonance Vibrations (Replies: 0)

  4. Forced Vibrations (Replies: 3)

Loading...