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 force

  1. Jul 30, 2006 #1
    A spring with length l = 8 cm hangs in
    vertical direction somewhere close the earth's surface. When a mass of m = 10 kg is attached
    to the spring its rest-position is at y0 = 11 cm. (a) Determine the spring constant k.

    i try to use F=-kx = mg where x=11cm - 8cm
    therefore,i would like to know whether my steps are correct or i used the wrong formula

    somebody pls help
     
  2. jcsd
  3. Jul 30, 2006 #2
    part b) The
    mass is pulled out of its rest-position by a distance Δy = 5 cm. What is the acceleration acting
    on the mass in the moment of its release?

    i got the answer of a=16.35m/s^2

    am i right??
     
  4. Jul 30, 2006 #3
    You're in the right direction :) Remember that at the spring its rest position [tex]F_{gr.} = F_{spring} = C \cdot u[/tex] where C = spring constant.

    So you need to solve: [tex] m \cdot g = C \cdot u[/tex] with u = distance of strecthing of the spring (3 cm)
     
  5. Jul 30, 2006 #4
    foir b i would say that you use the second law of Newton: [tex] F_{res} = m \cdot a[/tex]
     
  6. Jul 30, 2006 #5

    Doc Al

    User Avatar

    Staff: Mentor

    You are correct. (Except for that minus sign. Set the magnitude of the spring force equal to the magnitude of the weight.)
     
  7. Jul 30, 2006 #6

    Doc Al

    User Avatar

    Staff: Mentor

    Looks OK to me. (But next time don't just give your answer; show how you got your answer. :wink: )
     
  8. Jul 30, 2006 #7
    agrees with Doc Al :)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Spring force
  1. Spring Force (Replies: 1)

Loading...