1. Hey Guest! Check out the 3 MCAT Study Plan Options listed in the 'stickies' area at the top of the forums (BoomBoom, SN2ed, and MCATJelly). Let us know which you like best.

    Also, we now offer a MCAT Test-Prep Exhibitions Forum where you can ask questions directly from the test-prep services.
    Dismiss Notice
  2. Dismiss Notice
  3. Download free Tapatalk for iPhone or Tapatalk for Android for your phone and follow the SDN forums with push notifications.
    Dismiss Notice
Dismiss Notice

Interview Feedback: Visit Interview Feedback to view and submit interview information.

Interviewing Masterclass: Free masterclass on interviewing from SDN and Medical College of Georgia

Dismiss Notice
Hey Texans—join us for a DFW meetup! Click here to learn more.

kinetic energy/momentum conservation (rest mass energy)

Discussion in 'MCAT Discussions' started by IndyZX, Apr 30, 2004.

  1. IndyZX

    7+ Year Member

    Joined:
    Jan 19, 2003
    Messages:
    1,535
    Likes Received:
    3
    when an atom shoots off an alpha particle during alpha decay, is kinetic energy or momentum conserved?

    i say neither is conserved, what do you think?
     
  2. Note: SDN Members do not see this ad.

  3. liverotcod

    liverotcod Lieutenant Crunch
    10+ Year Member

    Joined:
    Nov 1, 2003
    Messages:
    2,336
    Likes Received:
    5
    Status:
    Attending Physician
    I think it would be:
    kinetic energy: no, because mass is being converted to kinetic energy
    momentum: yes, because the nucleus will recoil in response to the alpha particle ejection.
     
  4. IndyZX

    7+ Year Member

    Joined:
    Jan 19, 2003
    Messages:
    1,535
    Likes Received:
    3
    doesnt total mass increase? some of the weak nuclear force is coverted to mass i thought...
     
  5. UCLAstudent

    UCLAstudent I'm a luck dragon!
    10+ Year Member

    Joined:
    Sep 6, 2002
    Messages:
    5,046
    Likes Received:
    7
    Status:
    Resident [Any Field]
    Yes, I believe that this is correct.
     
  6. liverotcod

    liverotcod Lieutenant Crunch
    10+ Year Member

    Joined:
    Nov 1, 2003
    Messages:
    2,336
    Likes Received:
    5
    Status:
    Attending Physician
    I'm not 100% clear... but this site is helpful. There is mass lost in alpha decay, probably because of the decrease in potential energy in the parent nucleus after the decay.
     
  7. Nuel

    10+ Year Member

    Joined:
    Mar 8, 2003
    Messages:
    2,991
    Likes Received:
    1
    Mass is probably lost due to speed of these nuclear particles (dilation factor effect), especially electrons--decrease in potential energy which follows from increase in KE of the moving particles.

    I think I just rambled nonsense here :oops:
     
  8. Shrike

    Shrike Lanius examinatianus
    10+ Year Member

    Joined:
    Apr 23, 2004
    Messages:
    646
    Likes Received:
    4
    Everyone's got the right answer here (KE not conserved, because a massive particle is ejected; momentum conserved). Just wanted to point out: momentum is always conserved, as long as you're considering a closed system.
     
  9. IcedCube

    IcedCube Senior Member
    5+ Year Member

    Joined:
    Apr 18, 2004
    Messages:
    121
    Likes Received:
    0
    mcat knowledge in one ear, out the other.
     

Share This Page