Ask Question
22 March, 09:07

A Physicists often use a different unit of energy, the electron volt, when dealing wth e electron volt, abbreviated eV, is defined as the amount of kinetic energy gained by an electron upon accelerating through a 1.0 V potential difference. What is 1.0 electron volt in joules? at the atomic level. What is the speed of a proton with 2500 eV of kinetic energy? Express your answer with the appropriate units.

+1
Answers (1)
  1. 22 March, 12:59
    0
    Answer: 1ev = 1.609*10^-19 J

    velocity of electron = v = 2.97 * 10^7 m/s

    Explanation: The magnitude of an electronic charge (e) is given as

    e = 1.609*10^-19c

    The amount of kinetic energy an electron has when it moves through 1v equals the work done used in accelerating the electron (according to work - energy theorem).

    K. E = W = eV

    e = magnitude of electron = 1.609 * 10^-19c

    V = 1v

    Hence 1ev = 1.609 * 10^-19 * 1

    1ev = 1.609 * 10^-19 J.

    If K. E = 2500ev.

    By converting this to joules we have that

    If 1ev = 1.609 * 10^-19 J.

    Then 2500ev = 1.609 * 10^-19 * 2500

    K. E (in joules) = 4005 * 10^-19

    K. E = 4.005 * 10^-16 J.

    But K. E = 1/2mv²

    Where K. E = kinetic energy of electron = 4.005 * 10^-16 J.

    m = mass of electronic charge = 9.11 * 10 ^-31kg.

    By substituting the parameters, we have that

    4.005 * 10^-16 = 1/2 * 9.11 * 10 ^-31 * v²

    4.005 * 10^-16 * 2 = 9.11 * 10 ^-31 * v²

    8.01 * 10^-16 = 9.11 * 10^-31 * v²

    v² = 8.01 * 10^-16 / 9.11 * 10^-31

    v² = 0.879 * 10^15

    v² = 8.79 * 10^14

    v = √8.79 * 10^14

    v = 2.97 * 10^7 m/s
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “A Physicists often use a different unit of energy, the electron volt, when dealing wth e electron volt, abbreviated eV, is defined as the ...” in 📘 Physics if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers