1. Not finding help here? Sign up for a free 30min 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!

Simple Harmonic Motion, spring periods

  1. May 26, 2012 #1
    Hi guys! I'd really like help with this as I'm stuck.

    1. The problem statement, all variables and given/known data

    Investigate the mathmatical relationship between period of a spring and mass.
    Finding the spring constant (k) from measuring periods with a spring and different hanging masses.

    2. Relevant equations

    T = 2pi SQRT(m/k)

    or rearranged

    T^2 = ((4pi^2)/k) m

    3. The attempt at a solution

    Used Excel to plot T^2 vs. hanging mass. T^2 in seconds squared (y-axis) and hanging mass in kg (x-axis). Used Excel to find the best fit line.

    Since I have plotted T^2 vs. m, does the slope equal (4pi^2)/k ?

    I don't know where to go from here to get k though.



    ---

    I've attached the graph I did also
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     

    Attached Files:

  2. jcsd
  3. May 26, 2012 #2

    cepheid

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Welcome to PF!

    Yeah. The relationship is linear in m. All the stuff (the coefficient) that multiplies m is therefore the slope, just like in any other linear relationship.

    What do you mean? You have the slope, which is 4pi^2 /k, from the best fit line. Therefore, you have k.
     
  4. May 26, 2012 #3
    So, the slope is 1.5129, does that mean k is 1.5129 or

    is it (4pi^2)/1.5129 = k?

    thanks :)
     
  5. May 27, 2012 #4

    cepheid

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I'm not telling you the answer to that, you should be able to arrive at it using the information you have (and it should be really clear) . Consider these two statements:

    1. The slope is 4pi^2/k

    2. The slope is 1.5129 (according to the Excel best fit curve).

    What do you conclude?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook