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!

Ball compressing spring

  1. Mar 25, 2010 #1
    A ball of mass 0.25 kg is fired with velocity 120 m/s into the barrel of a spring gun of mass 1.8 kg initially at rest on a frictionless surface. The ball sticks in the barrel at the point of maximum compression of the spring. No energy is lost to friction. What fraction of the ball's initial kinetic energy is stored in the spring?
  2. jcsd
  3. Mar 25, 2010 #2
    You'll need inelastic collision conservation of momentum:
    (m1+m2)V_cen. of mass = m1v1 +m2v2

    And a translation into a center of mass reference frame:
    v'1 + v_cen. of mass = v1

    If you get the kinetic energy of the center of mass of the system before the collision that will be the kinetic energy that was lost into internal spring potential...

    Maybe there is an easier way, but I'm pretty sure this will get you the answer.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Ball compressing spring
  1. Spring max compression (Replies: 25)

  2. Compression of spring (Replies: 2)

  3. Compressed springs (Replies: 11)