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!

Spring Constant and Period

  1. Jan 26, 2010 #1
    1. The problem statement, all variables and given/known data

    A 200 g mass elongates a spring 3 cm from its equilibrium position. Find the spring constant (k) of the spring in N/m.

    An unknown mass is attached to the same spring and set in motion. If the period of oscillation is 3 seconds, find the value of the unknown mass in kg.

    2. Relevant equations

    k=mg/x
    T=2pi(sqrt)(m/k)

    3. The attempt at a solution

    I think I've determined part A to be 65.4 N/m. I did this by converting cm->m and g->kg. Then I filled it into the equation...

    k=.2(9.81)/.03 = 65.4 N/m

    Then I plug it into the other equation for part two of the question

    3=2pi(sqrt)m/65.4
    3/2pi (changed to .477 for ease)=sqrt(m/65.4)
    .477^2=(m/65.4)
    .22797=m/65.4
    .22797(65.4)=m
    m=14.91 kg

    Mostly what I'm asking for here is a confirmation on my work and if the m at the end of my second equation comes directly in kg or if it needs to be converted first.
     
  2. jcsd
  3. Jan 26, 2010 #2

    rl.bhat

    User Avatar
    Homework Helper

    Hi dynamity, welcome to PF.
    Your answer is correct. Final answer is in kg. No need to convert to any thing.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook