Kinetic Energy and a Collision

  1. 1. The problem statement, all variables and given/known data
    A 8.5 kg steel ball, travelling left to right at 12 m/s, undergoes an elastic collision with a 5 kg steel ball at rest. To the nearest Joule, what is the Total Kinetic Energy of the two balls after collision? If the first ball has a mass of 10 kg and the second ball is travelling at it with a speed of 3 m/s, what is the velocity, to one decimal place, of the first ball after collision? What is the velocity of the second ball to one decimal place?


    2. Relevant equations

    1/2mvi2+1/2mvii2=KE


    3. The attempt at a solution
    Question 1:
    1/2 (8.5)(122)= 612 J
    Question 2 & 3:
    I'm not sure the equation needed to solve for the needed. I'm pretty sure that if I can get question 2 then the same method will be used to solve question 3.
     
  2. jcsd
  3. kuruman

    kuruman 3,448
    Homework Helper
    Gold Member

    For questions 2 and 3 you need to conserve momentum in addition to energy conservation.
     
Know someone interested in this topic? Share a link to this question via email, Google+, Twitter, or Facebook