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: Hookes Law graph question

  1. Jun 14, 2012 #1
    1. The problem statement, all variables and given/known data
    3. The attempt at a solution


    Its question 1 A (III) I don't understand.

    I have included a copy of the question paper and the mark scheme.

    I understand the continuation of the straight line up to 800N however after does the line curve like the blue / red one on my diagram?

    I would have thought it should have leveled off at a constant length as after the spring is past the elastic limit it will only stretch so far before it turns into a straight bit of wire?

    The mark scheme would suggest that the spring should continue to stretch to infinity as more weights are added?


    Attached Files:

  2. jcsd
  3. Jun 14, 2012 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Once past the elastic limit the spring may stretch way more than per Hooke's law. And it won't return to it's unstretched length once the weight is removed. You are correct, of course, that at some point the spring may unravel and be nothing but a straight wire. I don't think they intend for the graph to go that far.
  4. Jun 14, 2012 #3
    So its the Red curve then?
  5. Jun 14, 2012 #4

    Doc Al

    User Avatar

    Staff: Mentor

    Yes, that's what I would say.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook