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: Compression distance

  1. Mar 12, 2010 #1
    Problem: An object of mass m1= 10 kg moving to the right with a velocity v1=30 m/s, collides with a second object of mass m2=5kg, which is initially at rest. The 2 objects stick together, and they continue to move with the same velocity V. The moving system of 2 blocks compresses a light spring, having a spring constant k=80 N/m. Calculate the max. compression distance x, of the spring.

    m1v1 + m2v2 = (m1+m2)vf
    (10)(30)+(5)(0)=(10+5)vf
    300=15vf
    Vf=300/15=20

    KE=U spring

    I stuck on how to finish solve the problem.
     
  2. jcsd
  3. Mar 12, 2010 #2
    You need to account for the energy stored in the spring. it is given by
    [tex]\frac{1}{2} k x^2[/tex]
    where k is the spring constant and x is the distance from the equilibrium position.
     
  4. Mar 13, 2010 #3

    Redbelly98

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    In other words, after you have found the 20 m/s velocity, this becomes an energy conservation problem to get the spring compression.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook