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nlexa [21]
3 years ago
15

Radioactive material disintegrates at a rate proportional to the amount currently present. If Q(t) is the amount present at time

t (in weeks), then dQ dt = −rQ, where r > 0 is the decay rate.
A) If 500 mg of a mystery substance decays to 83.01 mg in 5 weeks, determine the decay rate r.
B) Find an expression for the amount of this substance present at any time t.
C) Find the time required for the substance to decay to one-half its original amount.

Mathematics
1 answer:
stepladder [879]3 years ago
3 0

Answer:

Step-by-step explanation:

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The given geometric series as shown in the question is seen to; Be converging with its' sum as 81

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We are given the geometric series;

27 + 18 + 12 + 8 + ...

Now, we see that;

First term; a₀ = 27

Second Term; a₁ = 2(27/3)

Third term; a₂ = 2²(27/3²)

Fourth term; a₃ = 2³(27/3³)

Thus, the formula is;

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Applying limits at infinity gives;

2^(∞) * (27/3^(∞)) = 0

Since the  terms of the series tend to zero, we can affirm that the series converges.

The sum of an infinite converging series is:

S_n = a/(1 - r)

S_n = 27/(1 - (2/3)

S_n = 81

Read more about converging or diverging series at; brainly.com/question/15415793

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2 years ago
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Cross off alphabetically ascending (1 way), and alphabetically
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steps:
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What does this problem equal?show your work.<br><br>-12(k+4)=60
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Hey there!

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