Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie

Momentum of a proton

Options
  • 15-10-2011 4:48pm
    #1
    Smythe
    Registered Users Posts: 434 ✭✭


    A proton of rest mass 1.67 x 10^-27 kg is moving at a constant speed of 0.7c

    What is it's momentum?
    Using E = γmc^2 I obtained;

    E = 2.10 x 10^-10 J


    Then with;

    E^2 = (pc)^2 + (mc^2)^2 and solving for p I got;

    p = 4.88 x 10^-19

    What do you think of my attempt?


Comments

  • Options
    #2
    Morbert
    Registered Users Posts: 3,457 ✭✭✭Morbert


    Smythe wrote: »
    Using E = γmc^2 I obtained;

    E = 2.10 x 10^-10 J


    Then with;

    E^2 = (pc)^2 + (mc^2)^2 and solving for p I got;

    p = 4.88 x 10^-19

    What do you think of my attempt?

    That is correct, but you could have used the relativistic momentum equation.

    p = γmv = 4.9 x 10^-19


  • Options
    #3
    Smythe
    Registered Users Posts: 434 ✭✭Smythe


    Morbert wrote: »
    That is correct, but you could have used the relativistic momentum equation.

    p = γmv = 4.9 x 10^-19
    That would probably be a more sensible way to go about it.


Advertisement