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!

Grr springs

  1. Jul 23, 2004 #1
    hello there
    consider a spring that is fixed to a point (i have tried to draw a picture, so to make it clearer as to what i am talking about) that rotates anti clockwise in a horizontal fashion. there is a ball on the end of the spring with mass m, the spring has spring constant k and unstretched length L and the ball moves with angular velocity omega
    i am trying to find an expression for theta, the angle that the spring makes with the vertical, as a function of L, w, k, m and g.
    me being a maths student and not a physics student just treated this as simaltaneous equations and plugging some stuff together using

    W=F*s *cos(theta)
    F=m*v^2/L where v is the velocity perpendicular to the centripetal force
    F=-k*theta

    after a bit of algebra we get that
    cos(theta)=-k/(L^2*m*omega^2)
    of course one can arrange for theta but i am not sure if this expression is correct, more than likely it is wrong. so if someone could shed some lighton the matter it would be greatly appreciated.

    thanks
     

    Attached Files:

    Last edited: Jul 23, 2004
  2. jcsd
  3. Jul 23, 2004 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Here's how I would approach this problem. Apply Newton's 2nd law to the vertical and horizontal forces on the mass:
    [itex]T sin\theta = mg[/itex], where T is the tension in the spring
    [itex]T cos\theta = m\omega^2 R[/itex], where R is the radius of circle
    Combine this with what you know about the spring: its length is L + T/k, thus [itex]R = (L + T/k)sin\theta[/itex].

    You should be able to solve this for for [itex]\theta[/itex], but it looks messy.
     
  4. Jul 24, 2004 #3
    thanks for the helpful advice
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Grr springs
  1. Mass on a spring (Replies: 6)

  2. Spring Pendulum (Replies: 1)

  3. Pulleys and spring (?) (Replies: 2)

  4. Spring Gun (Replies: 5)

Loading...