Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Swing Problem -

  1. Oct 30, 2005 #1
    Swing Problem --

    Im looking at a swing problem with a swing at some angle theta from vertical. The swing is massless and a child with weight W sits at the end of the swing. How do i find the tension of the swing? Likewise, when the swing is vertical?

    Thanks!:smile:
     
  2. jcsd
  3. Oct 30, 2005 #2

    Päällikkö

    User Avatar
    Homework Helper

    You should divide the forces into x and y components. What do you think would be the best directions for x and y?
     
  4. Oct 30, 2005 #3
    I tried, but i got something like the x component of tension being the Force Applied/sin theta and the y component being the weight over sine theta or something like that, but i need to find it in terms of weight and theta.

    Thanks for your help!
     
  5. Oct 31, 2005 #4

    Päällikkö

    User Avatar
    Homework Helper

    Try with y being into the rope's direction.
    What then should forces in that direction equal?
     
  6. Oct 31, 2005 #5
    Ok, think about this: When the child sits on the swing at rest, what are the forces acting on the child on the swing? At least one contact(tension)force and one non-contact(weight) force. (Is there normal force, if not, then tension force and weight force are equal and opposite right?)

    Now the child is in motion. On standard x-y axis, the weight is straight down and tension is [tex]\theta[/tex] from the vertical. Now use your vast knowledge of trigonometry(or even geometry) to find where that angle goes, and set the sum of the forces in the x-direction and y-direction
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook