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Calculate velocity of a 1MeV Neutron

  1. Aug 26, 2014 #1
    How would one calculate the velocity of a 1MeV neutron??

    I tried the following the attached formula for V/C but E is less than the rest mass which yields the square root of a negative number. Not sure what to do for this

    Attached Files:

  2. jcsd
  3. Aug 26, 2014 #2


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    Staff: Mentor

    1 MeV here is surely the kinetic energy, not the total (rest plus kinetic) energy.
  4. Aug 26, 2014 #3
    It doesn't say. I guess that I will assume such. Is the 'E' in the equation I am using for the rest mass energy plus the kinetic energy?
  5. Aug 26, 2014 #4


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    Since a neutron has a higher rest mass than 1MeV, then one should safely assume that kinetic energy is what is meant here.

    The E in that equation is indeed the rest+kinetic energy.
  6. Aug 27, 2014 #5


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    Since the neutron rest mass is approximately 940 Mev, you probably could use E=(mv^2)/2 to get v. (v=c/22?).
    Last edited: Aug 27, 2014
  7. Aug 27, 2014 #6


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    I agree that a nonrelativistic approach should be fine - it is a very good approximation.
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