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: Oscillations of a mass on a spring.

  1. Apr 18, 2007 #1
    A mass m suspended from a spring of constant k has a period T. If a mass M is added, the period becomes 3T. Find M in terms of m.


    I know that the period varies as the square root of the mass so the mass M should be 9 times that of m. The answer is M=8m. I dont know why it is 8 instead of 9. Any help would be appreciated.

    Last edited: Apr 18, 2007
  2. jcsd
  3. Apr 18, 2007 #2


    User Avatar
    Homework Helper

    Your equation is a bit wrong (typo, maybe?), T=2pi(m/k)^(1/2). Have you worked it out mathematically? You will get M=8m. Remember that the total mass is M + m for when the period is 3T. Try to work it out.
  4. Apr 18, 2007 #3
    Nice. Inserting M+m then solving works. Thank you.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook