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anonymous

  • one year ago

A 39 gram sample of a substance that's a by-product of fireworks has a k-value of 0.1024. N = N0e -kt N0 = initial mass (at time t = 0) N = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days Find the substance's half-life, in days. Round your answer to the nearest tenth.

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  1. anonymous
    • one year ago
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    please help

  2. anonymous
    • one year ago
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    @puppylover52

  3. puppylover52
    • one year ago
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    srry idk this one

  4. IrishBoy123
    • one year ago
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    the equation is \[\frac{N(t)}{N_o} = e^{-kt}\] set N /No to 1/2 and that is what half life means, the time for the amount to halve \[\frac{1}{2} = e^{-0.1024T}\] take logs and solve for T, where t = T is the half life

  5. Jack1
    • one year ago
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    nice work @IrishBoy123 !

  6. anonymous
    • one year ago
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    so the answer cause I cant solve it?

  7. anonymous
    • one year ago
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    @IrishBoy123 @Jack1

  8. anonymous
    • one year ago
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    i solved for t and its still not it

  9. Jack1
    • one year ago
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    i think u use t to solve the 1/2 life... yeah?

  10. Jack1
    • one year ago
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    no, in irish's example: t is the half life

  11. anonymous
    • one year ago
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    can you find the answer @Jack1 ?

  12. Jack1
    • one year ago
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    yeah, i have the answer, what did u get for t?

  13. anonymous
    • one year ago
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    like 6.790

  14. Jack1
    • one year ago
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    yep, same here, exact answer for half life is t=6.76902 ish

  15. Jack1
    • one year ago
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    all i have is grams tho, i don't know the units of k, so i have no idea of the units of t or if k and t are both in the same units of measure...?

  16. Jack1
    • one year ago
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    (eg if k's relates to pounds/second or something and our No is in grams we have a problem)

  17. anonymous
    • one year ago
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    so you think you can solve it?

  18. anonymous
    • one year ago
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    @IrishBoy123

  19. Jack1
    • one year ago
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    lol... wat? so 6.8 isnt ur answer? (rounded to the nearest tenth)

  20. anonymous
    • one year ago
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    lol it is now my computer got messed up so it was saying everything incorrect thanks @Jack1

  21. Jack1
    • one year ago
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    ha. s'cool ;)

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