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: Springs, mass, speed.

  1. Feb 1, 2010 #1
    1. The problem statement, all variables and given/known data
    a 300 g mass vibrates at the end of a horizontal spring along a frictionless surface. if the spring constant is 45N/m, and the maximum displacement of the mass is 8.0cm, what is the maximum speed of the mass?

    2. Relevant equations


    3. The attempt at a solution
    do i rearrange the formula to solve for m. so it becomes m=r^2(g)/G. that only gives me the mass tho. how do i solve for the speed??
  2. jcsd
  3. Feb 1, 2010 #2
    I don't even know what you're doin.

    Find the acceleration with F_spring=kx and F=ma.

    When is the spring traveling the fastest? You should use (or combine) 3 equations to get your answer. I gave you 2.
  4. Feb 1, 2010 #3
    ok so,
    Fspring= 45N/m(0.08m) whick is 3.6N. then arrange f=ma to solve for a, which is a=3.6N/0.3Kg, so the a is 12. then do i use the formula Vf^2=Vi^2 + 2ad. so,i would square root (2)(12)(0.08) to get 1.4 m/s as the maximum speed?
  5. Feb 1, 2010 #4
    if "maximum displacement" means the distance from where the spring is uncompressed, to it's maximum compression.. then yes that's right.
  6. Feb 1, 2010 #5
    Thank you so much :)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook