Hey there! Sign in to join this conversationNew here? Join for free

Quantum question Watch

Announcements
    • Thread Starter
    Offline

    0
    ReputationRep:
    When an electron annihilates a positron, two photons are produced, each with an energy of 511keV. Calculate the frequency of each photon.
    • Aston Villa FC Supporter
    Offline

    3
    ReputationRep:
    (Original post by harryabel62)
    When an electron annihilates a positron, two photons are produced, each with an energy of 511keV. Calculate the frequency of each photon.

    E = hf.

    Since we know E (511keV x 2 = 1022keV), and we know h (6.67 x 10^-34), we can work out f by rearranging:

    f = E/h.

    Can you do it now?
    Offline

    2
    ReputationRep:
    (Original post by Kyx)
    E = hf.

    Since we know E (511keV x 2 = 1022keV), and we know h (6.67 x 10^-34), we can work out f by rearranging:

    f = E/h.

    Can you do it now?
    I am pretty sure you do not multiply it by 2 as it says in the question "EACH PHOTON has an energy of 511Kev"
    Offline

    2
    ReputationRep:
    (Original post by Kyx)
    E = hf.

    Since we know E (511keV x 2 = 1022keV), and we know h (6.67 x 10^-34), we can work out f by rearranging:

    f = E/h.

    Can you do it now?
    Also it's not 6.67 is 6.63 for planks constant
    • Aston Villa FC Supporter
    Offline

    3
    ReputationRep:
    (Original post by Kyx)
    E = hf.

    Since we know E (511keV), and we know h (6.63 x 10^-34), we can work out f by rearranging:

    f = E/h.

    Can you do it now?
    Fixed
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    How are your GCSEs going so far?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.