I tried solving this question, but I couldn't get the answer. Please help!?

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  • Alan
    Lv 7
    4 months ago

    See this reference 

    https://www.bartleby.com/solution-answer/chapter-3...

    Part A 

    It says for maximum reflection 

    2nt = mλ_subR 

    t = mλ_subR /2n 

    λ_subR = wavelength of maximum reflect 

    n = index of refraction of the film 

    t = thickness  

    m = is a integer   

    for no reflection 

    2nt = (m+ 1/2)λ_subNR 

    since 2nt =2nt 

    you can solve for m 

    mλ_subR = (m+ 1/2)λ_subNR 

    m(λ_subR - λ_subNR ) =  (1/2)λ_subNR 

    m =   (1/2)λ_subNR/  ( λ_subR - λ_subNR )

    m  = (1/2)548/ (640-548) =   2.97826087

    so rounding error would indicate m = 3 

    t = 3*640/ (2*1.20) =    800 nm

  • Anonymous
    4 months ago

    It's a physics problem, not a math problem.

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