Results 1 to 6 of 6

Math Help - Alpha Particles? (Don't really know a good title for this)

  1. #1
    Super Member Aryth's Avatar
    Joined
    Feb 2007
    From
    USA
    Posts
    652
    Thanks
    2
    Awards
    1

    Alpha Particles? (Don't really know a good title for this)

    A steady beam of alpha particles (q = +2e) traveling with constant kinetic energy 20 MeV carries a current of 0.25 \mu A.

    (a) If the beam is directed perpendicular to a flat surface, how many alpha particles strike the surface in 3.0s?

    (b) At any instant, how many alpha particles are there in a given 20 cm length of the beam?

    (c) Through what potential difference is it necessary to accelerate each alpha particle from rest to bring it to an energy of 20 MeV?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by Aryth View Post
    A steady beam of alpha particles (q = +2e) traveling with constant kinetic energy 20 MeV carries a current of 0.25 \mu A.

    (a) If the beam is directed perpendicular to a flat surface, how many alpha particles strike the surface in 3.0s?

    (b) At any instant, how many alpha particles are there in a given 20 cm length of the beam?

    (c) Through what potential difference is it necessary to accelerate each alpha particle from rest to bring it to an energy of 20 MeV?
    (a) Note that Amp = C/sec ..... So convert q into Coulomb and divide that answer into 0.25 x 10^-6. Then multiply by 3.

    (b) Calculate the speed of an alpha-particle and hence calculate the time it takes to travel 20 cm. Then calculate how many alpha particles strike the surface in that time.

    (c) Is it over a particular distance?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member Aryth's Avatar
    Joined
    Feb 2007
    From
    USA
    Posts
    652
    Thanks
    2
    Awards
    1
    (a) I got it, thanks

    (b) We're studying circuits, Loops, Ohm's Law and all that... I don't have a formula or anything for \alpha-particles...

    (c) It has no distance measurement. That's all it gives us.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by Aryth View Post
    (a) I got it, thanks

    (b) We're studying circuits, Loops, Ohm's Law and all that... I don't have a formula or anything for \alpha-particles... Mr F says: Get the speed using the known K.E.

    (c) It has no distance measurement. That's all it gives us.
    I'll try to post on (c) later as I have no time now.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Super Member Aryth's Avatar
    Joined
    Feb 2007
    From
    USA
    Posts
    652
    Thanks
    2
    Awards
    1
    Awesome. I got b, thanks again. I have been pounding at c and can't figure it out...
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Member TheMasterMind's Avatar
    Joined
    Dec 2008
    Posts
    155
    Quote Originally Posted by Aryth View Post
    Awesome. I got b, thanks again. I have been pounding at c and can't figure it out...
    Consider this:

    E=Vq<br />

    V=\frac{E}{q}

    E=20MeV and q=2e
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Let alpha be a real number, alpha > -1 now show that
    Posted in the Differential Geometry Forum
    Replies: 6
    Last Post: November 27th 2011, 08:14 PM
  2. Replies: 1
    Last Post: November 14th 2011, 03:48 AM
  3. good books forbiing really good at math and physics
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: August 22nd 2009, 04:26 PM

Search Tags


/mathhelpforum @mathhelpforum