1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Angular distance question - how to solve

  1. May 20, 2016 #1
    • Poster has been reminded to post schoolwork in the Homework Help forums and show their work
    during knee flexion of a squat phase the knee moves from 180 degrees to 95 degrees. if you perform 10 complete squats what is the total angular distance (in radians and in degrees), undergone at the knee?

    anyone know how to solve this one? can you explain
  2. jcsd
  3. May 20, 2016 #2
    If I understood it correctly:
    -If you pay regard to the sign, then 0deg and 0rad.
    -If you only count one direction, then 10*(180-95)=850deg=14,84 rad.
  4. May 20, 2016 #3
    that is the answer i got, but the answer key has 1700 degrees for total distance and 29.67 rad. so i was not sure if i was missing something here.
  5. May 20, 2016 #4
    here is the sheet if you want to look it

    Attached Files:

  6. May 20, 2016 #5
    Then they calculated both directions, without looking at the signs. Yes, this is indeed the third possibility :)
  7. May 20, 2016 #6
    but why calculate both directions? so in essence, it is 850 x 2 = 1700. Do you know when you have to calculate both directions?
  8. May 20, 2016 #7
    I don’t know… really… I only know the physics part… Probably if you want to calculate how much your knee was ‘used’
  9. May 20, 2016 #8


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    This is the angular analog of linear distance.

    If you walk 1 mile to the store and then back home every day for a week, what is the total distance you walk?

    You count the distance both there and back, and then add those for 7 days.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted