Chromium 51 is a radioactive substance used in medicine. It has a 1/2 life of 28 days. The equation for its exponential decay model is `y=a(.5)^t/28 If 10 mg is ingested by a patient, how many days before only 8 mg is still emitting radiation?

Answers

Answer 1

Answer:

9 days before only 8 mg is still emitting radiation.

Step-by-step explanation:

The exponential model is:

[tex]y(t) = a(0.5)^{\frac{t}{28}}[/tex]

In which a is y(0), that is, the initial quantity.

10 mg is ingested by a patient

This means that [tex]a = 10[/tex], and thus:

[tex]y(t) = 10(0.5)^{\frac{t}{28}}[/tex]

How many days before only 8 mg is still emitting radiation?

This is t for which y(t) = 8. So

[tex]y(t) = 10(0.5)^{\frac{t}{28}}[/tex]

[tex]8 = 10(0.5)^{\frac{t}{28}}[/tex]

[tex](0.5)^{\frac{t}{28}} = \frac{8}{10}[/tex]

[tex](0.5)^{\frac{t}{28}} = 0.8[/tex]

[tex]\log{(0.5)^{\frac{t}{28}}} = \log{0.8}[/tex]

[tex](\frac{t}{28})\log{0.5} = \log{0.8}[/tex]

[tex]\frac{t}{28} = \frac{\log{0.8}}{\log{0.5}}[/tex]

[tex]t = 28\frac{\log{0.8}}{\log{0.5}}[/tex]

[tex]t = 9[/tex]

9 days before only 8 mg is still emitting radiation.


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Kindly check explanation

Step-by-step explanation:

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A.)

Vehicle speeds on highway (9 vehicles) 74, 82, 67, 73, 65, 41, 74, 49, 85

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Answers

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