1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Minimum energy a proton must have to penetrate

  1. Sep 12, 2010 #1
    Minimum energy a proton must have to penetrate....

    1. The problem statement, all variables and given/known data

    Determine the minimum energy that a proton must have to penetrate 30 cm of tissue, the approximate thickness of the human body.

    2. Relevant equations
    I used R=[(E/9.29)^1.8]1.11x10^-3 but I'm not sure if this is correct.


    3. The attempt at a solution

    R=[(E/9.29)^1.8]1.11x10^-3
    30 cm=3 mm

    3mm=[(E/9.29)^1.8]1.11x10^-3, then I divided by 1.11x10^-3 to get 27027.70mm=(E/9.29)^1.8
    Then I took a root to the 1.8 power and got 80.64mm=E/9.29
    I then multiplied by 9.29 to get 749 mEV.

    Seems a bit high. Wasn't sure about units or if I even used the correct formula?
    Thanks for your help!
     
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted