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    so i need help with this question and im too frustrated to think straight, i think i have some answers but there probably wrong. So here it is

    The stopping potential when a frequency of 1.61*10^15 Hz is shone on a metal is 3V

    a) what is energy transferred by each photon ?
    b)calculate the work function of the metal
    c)What is the maximum speed of the ejected electrons
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    (Original post by nebbercracker)
    so i need help with this question and im too frustrated to think straight, i think i have some answers but there probably wrong. So here it is

    The stopping potential when a frequency of 1.61*10^15 Hz is shone on a metal is 3V

    a) what is energy transferred by each photon ?
    b)calculate the work function of the metal
    c)What is the maximum speed of the ejected electrons
    Right down the answers you have got, and I'll see if they match with mine. Also did you use the correct equations? And if you did, what equations did you use?
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    (Original post by Reety)
    Right down the answers you have got, and I'll see if they match with mine. Also did you use the correct equations? And if you did, what equations did you use?
    well for part a i did E=hv so energy = planks * velocity which for a photon is the speed of light

    6.63*10^-34 x 300,000,000 m/s = 1.989*10^-25

    then for part b i used the equation work function = hf-E so planks * frequency - energy

    6.63*10^-34 x 1.61*10^15 - 1.989*10^-25 = 1.0674*10^-18

    for part c I didn't know what equation to use and it was pretty late at night when i attempted all this so i gave up.
    So do these two answers seem right ?
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    (Original post by nebbercracker)
    so i need help with this question and im too frustrated to think straight, i think i have some answers but there probably wrong. So here it is

    The stopping potential when a frequency of 1.61*10^15 Hz is shone on a metal is 3V

    a) what is energy transferred by each photon ?
    b)calculate the work function of the metal
    c)What is the maximum speed of the ejected electrons
    a) E = hf
    b) E_kmax = hf - (phi)
    c) E)kmax = hf - (phi) where E_kmax = 1/2 m v^2
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    (Original post by nebbercracker)
    so i need help with this question and im too frustrated to think straight, i think i have some answers but there probably wrong. So here it is

    The stopping potential when a frequency of 1.61*10^15 Hz is shone on a metal is 3V

    a) what is energy transferred by each photon ?
    b)calculate the work function of the metal
    c)What is the maximum speed of the ejected electrons
    a) E = hf

    b) hf = work function - KE (max) ==> KE (max) = work function - hf

    However, the KE (max) of the electron = eV, where V is the stopping potential.

    Therefore, KE max = 1.6 x 10^(-19) x 3

    c) KE max = 0.5 x m x v^2, and just rearrange to find v.
 
 
 
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