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Ball Hitting Stationary Blocks

  1. Jun 14, 2015 #1
    1. The problem statement, all variables and given/known data

    Objects A and C are made of different materials, with different “springiness,” but they have the same mass and are initially at rest. When ball B collides with object A, the ball ends up at rest. When ball B is thrown with the same speed and collides with object C, the ball rebounds to the left. Compare the velocities of A and C after the collisions. Is vA greater than, equal to, or less than vC?

    1. vA > vC

    2. vA = vC

    3. vA < vC

    2. Relevant equations


    3. The attempt at a solution

    I thought that since the ball stopped in the case of A, all of the energy would be transferred to A and that it would have the higher final velocity. However, the correct answer was tha vC was greater than vA and I wasn't sure why

  2. jcsd
  3. Jun 14, 2015 #2


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    Homework Helper

    The energy need not conserve during a collision, but the momentum conserves. Which of A and C get greater momentum during the collision?
  4. Jun 17, 2015 #3
    Ah I get it,

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