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Zina [86]
4 years ago
6

How long will it take for the 1.35-mg sample of 236Pu in Example 19.4 to decay to 0.100 mg? (The half-life of plutonium-236 is 2

.86 yr.) Express the time in years to three significant figu
Mathematics
1 answer:
dedylja [7]4 years ago
6 0

Answer:

  10.7 years

Step-by-step explanation:

The decay equation can be written as ...

  remaining = initial × (1/2)^(t/(half-life))

Filling in the given values, we can solve for t.

  0.100 = 1.35 × (1/2)^(t/2.86)

  0.100/1.35 = (1/2)^(t/2.86) divide by 1.35

Taking logs transforms this to a linear equation:

  log(0.100/1.35) = (t/2.86)log(1/2)

Since log(a/b) = -log(b/a), we can multiply both sides by -1 and simplify the logs a bit.

  log(1.35/.1) = t·(log(2)/2.86)

  2.86·log(13.5)/log(2) = t ≈ 10.7 . . . . years

The decay time is about 10.7 years.

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The class average on a math test was an 82 with a standard deviation of 5. If the 
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Answer:

Option 3 and 4.

Step-by-step explanation:

The z score shows by how many standard deviations the raw score is above or below the mean. The z score is given by:

z=\frac{x-\mu}{\sigma} \\\\where\ x=raw\ score,\mu=mean, \ \sigma=standard\ deviation

Given that mean (μ) = 82, standard deviation (σ) = 5

1) For x = 74:

z=\frac{x-\mu}{\sigma} \\\\z=\frac{74-82}{5} =-1.6

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z=\frac{x-\mu}{\sigma} \\\\z=\frac{87-82}{5} =1

From the normal distribution table, P(x < 87) = P(z < 1) = 0.8413 = 84.13%

Option 2 is incorrect

3) For x = 95:

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Option 3 is correct

4) For x < 77

z=\frac{x-\mu}{\sigma} \\\\z=\frac{77-82}{5} =-1

From the normal distribution table, P(x < 77) = P(z < -1) = 0.16 = 16%

Option 4 is correct

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8 0
3 years ago
Tell which line contains each point for triangle ABC.
gavmur [86]

5. The line that contains the circumcenter in ΔABC is: <em>line k.</em>

6. The line that contains the orthocenter in ΔABC is: <em>line m.</em>

7. The line that contains the centroid in ΔABC is: <em>line l.</em>

8. The line that contains the centroid in ΔABC is: <em>line n.</em>

<h3>What is the Circumcenter of Triangle?</h3>

Circumcenter is the point where all three perpendicular bisectors of the three sides of a triangle meet and they are of equal distance from the three vertices of the triangle.

  • The line that contains the circumcenter in ΔABC is: <em>line k.</em>

<h3>What is the Orthocenter of a Triangle?</h3>

Orthocenter is the point in a triangle where the three altitudes that are perpendicular to the opposite sides and connect with the vertices of the triangle intersect.

  • The line that contains the orthocenter in ΔABC is: <em>line m.</em>

<h3>What is the Centroid of a Triangle?</h3>

The centroid of a triangle is a the point of intersection where all three medians of a triangle. Medians of a triangle connects the vertices to the midpoints of the opposite sides of a triangle.

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<h3>What is the Incenter of a Triangle?</h3>

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Learn more about centers of a triangle on:

brainly.com/question/16045079

5 0
3 years ago
Quick i need help thank you, i wil give branliest
ladessa [460]

alr thanks for the free points

8 0
3 years ago
Read 2 more answers
What is the slope of the line described by the equation below?<br> y-5 = 6(x-4)
Aneli [31]

Answer:

6

Step-by-step explanation:

To solve this, you need to have your equation in slope-intercept form.  This is y=mx+b, where m is the slope and b is the y-intercept.

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The slope, m, is equal to 6.

7 0
3 years ago
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