3 years ago

A 20mg sample of thorium-233 decays to 17mg after 5 min. determine the half life of thorium-233?

1 answer:

3 0

Let r be the decay rate (time in minutes) 17 = 20 e^(5r) 0.85 = e^(5r) ln 0.85 = 5r similarly, ln 0.5 = hr ... where h is the half-life, so dividing the 2 equations, ln 0.85 / ln 0.50 = 5r / hr = 5/h h = 5 ln 0.50 / ln 0.85 h = 21.3 min b) 1/20 = 0.05, so ln 0.85 = 5r ln 0.05 = tr t = 5 ln 0.05 / ln 0.85 t = 92.2 min

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lara [203]

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3 years ago

(20n^2+N^3+10n^2) /10N^2

kirill115 [55]

Combine like terms:
n^3 + 20n^ + 10n^2
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Divide:
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Factor:
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2 years ago

write a function that transforms f(x)=2^3+4 in the following way: stretch vertically by a factor of 6 and shift 5 units left.

maksim [4K]

Answer:

f(x) = 2x3 + 4

Stretch vertically be a factor of 2:

f(x) = 2*2x3 + 4 = 4x3 + 4

Shift 5 units to the left:

f(x) = 4(x+5)3 + 4

8 0

1 year ago