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: Spring & mass

  1. Mar 9, 2014 #1
    I'm a mechanical engineer from Norway who has an work related query.
    Please see the attached picture describing the problem.

    I'm trying to figure out how heigh mass 1 travels if mass 2 is quick released when being suspended in a spring. I'm also trying to figure out a the maximum acceleration, but thats 2. priority.

    I have tried to work out an answer my self, but I don't think it's correct.
    The thing I can't get my head around is how to calculate the height mass 1 travels above it's equilibrium due to the speed and spring tension. If the mass 2 had been release slowly, the answer could easily be found using the energy forumula(E=1/2*k*x^2), as far as I can understand.

    Any bright minds who could spare a few minutes explaining me this?

    Help is much appreciated!

    Have a nice sunday.

    Attached Files:

  2. jcsd
  3. Mar 9, 2014 #2


    User Avatar
    Science Advisor
    Homework Helper

    Hi Emilsen! Welcome to PF! :smile:

    I think "quick release" simply means that M2 starts going down, and M1 starts going up.

    So you can use conservation of energy (for M1 and the spring).
  4. Mar 10, 2014 #3
    Hi tiny-tim,
    Thanks for your reply.

    I have tried the following equation setup:

    I used F=kx to find x1 and x2 for mass 1+2 and mass 1.

    I then tried the following formula to calculate how heigh the mass 1 went above the E2spring equilibrium:
    v2=v1-gs/v1=0, to find s.

    Is this the right path?
  5. Mar 10, 2014 #4


    User Avatar
    Science Advisor
    Homework Helper

    Hi Emilsen! :smile:
    nooo …

    v is irrelevant, since the system both starts and finishes with v = 0

    and what about gravity? :wink:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted