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!

What is the speed of the 8-ball after the collision?

  1. Oct 21, 2014 #1

    1. In a pool game, the cue ball, which has an initial speed of 1.3 m/s, makes an elastic collision with the 8-ball, which is initially at rest. After the collision, the 8-ball moves at an angle theta = 33.2o with respect to the original direction of the cue ball, as shown in the figure. Assume the pool table is frictionless and the masses of the cue ball and the 8-ball are equal. What is the speed of the 8-ball after the collision?

      prob11a.gif






    2. Mgh + W = 1/2mv^2
    p=mv



    3. I was easily able to get that phi was 56.8 deg because of the 90 deg angle. Now I am lost at how to find the velocity of the 8 ball without the velocity of the cue ball???
     
  2. jcsd
  3. Oct 21, 2014 #2

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Hello White and welcome to PF :-)

    Your collection of relevant equations needs revision and extension. Mgh and W are unlikely to play a role in this drama....
     
  4. Oct 28, 2014 #3

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    Conservation of momentum and energy are most important. But "Mgh" is irrelevant here. It is the potential energy of a mass M at height h, but there is no "height" here.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: What is the speed of the 8-ball after the collision?
Loading...