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!

Ideal Spring Problem

  1. Dec 8, 2014 #1
    1. The problem statement, all variables and given/known data
    An ideal spring hangs next to a scale, when a 100N weight the scale reads 40, when a 200N weight is attached it reads 60. Using an unknown weight reads 30.

    2. Relevant equations

    3. The attempt at a solution
    I attempted to find the value of k for the spring however when calculating k for the 100N it is 2.5N/m and for the 200N it is 3.3N/m which doesn't make sense to me since I would've thought k would be constant. I also tried using F/x=F/x but this also didn't work so I'm completely lost.
  2. jcsd
  3. Dec 8, 2014 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Hint: you are not told what the scale reads when no weight is attached.
  4. Dec 8, 2014 #3
    Thanks! I solved for the constant weight that is being applied to the scale.
    This gave c=100
    Including this constant weight in the equations gave the correct scale reading of 50.
    I'm assuming this is how you would solve it because it produced the correct answer although there might be a different way.
  5. Dec 8, 2014 #4


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    That's as good a way as any.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Discussions: Ideal Spring Problem
  1. Ideal Springs (Replies: 3)

  2. Ideal Spring Problem (Replies: 4)

  3. Ideal Spring (Replies: 3)