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3 years ago

5

How long will it take for a radioactive isotope with a decay constant of 0.15 (which means a half life of 4.6 days ) to decay to

5% of its original value?

1 answer:

jek_recluse [69]3 years ago

6 0

Radioactive decay is given by:
N = No x e^(-λt)
We know that N/No has to be 0.05
λ = 0.15
0.05 = e^(-0.15t)
t = ln(0.05)/(-0.15)
t = 19.97 days

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if the coefficient of linear expansion of a metal is 2.05× 10^-6 k^-1 what will be its new length if 50cm metal went through a t

boyakko [2]

Answer:

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2 years ago

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3 years ago

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xxMikexx [17]

Answer:

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We can calculate the angle ECD:

$tan(\hat{ECD}) = \frac{ED}{EC} = \frac{100}{50} = 2$

$\hat{ECD} = tan^{-1} 2 = 63.43^o$

This is also the angle ACB, so we can find the length AB:

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$2 = \frac{AB}{234}$

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