The half-life of radium-226 is 1620 yr. Given a sample of 1 g of radium-226, the quantity left Q(t) (in g) after t years is given by:

Q(t)= 1/2^t/1620

Required:
a. Convert this to an exponential function using base e.
b. Verify that the original function and the result from part (a) yield the same result for Q(0), Q(1620), and Q(3240).

Answers

Answer 1

Answer:

(a)[tex]e^{-0.000428 t}[/tex]

Step-by-step explanation:

We are given that

Half life of radium-226=1620 yr

The quantity left Q(t) after t years is given by

[tex]Q(t)=(\frac{1}{2})^{\frac{t}{1620}}[/tex]

a. We have to convert the given function into an exponential function using base e.

[tex]Q(t)=(\frac{1}{2})^{\frac{t}{1620}}[/tex]

=[tex]((\frac{1}{2})^t)^{\frac{1}{1620}[/tex]

=[tex]e^{ln(1/2) t/1620}[/tex]

[tex]=e^({\frac{ln(1/2)}{1620}t)[/tex]

=[tex]e^{-0.000428 t}[/tex]

(b)

[tex]Q(0)=e^{-0.000428 \times 0}[/tex]

=1

From original function

Q(0)=1

[tex]Q(1620)=(\frac{1}{2})^{\frac{t}{1620}}[/tex]

[tex]Q(1620)=\frac{1}{2}=0.5[/tex]

From exponential function

[tex]Q(1620)=e^{-0.000428 \times 1620}[/tex]

[tex]=0.499\approx 0.5[/tex]

[tex]Q(3240)=(\frac{1}{2})^{\frac{3240}{1620})=0.25[/tex]

[tex]Q(3240)=e^{-0.000428 \times 3240}[/tex]

Q(3240)=0.249=[tex]\approx 0.25[/tex]

Hence, verified.


Related Questions

Evaluate if 8y + 4x – (2x + 3) if x = – 2 and y = 6

Answers

Answer:

41

Step-by-step explanation:

substitute x=-2 and y=6, we know

8×6 +4×(-2) -(2×(-2) +3) = 48-8-(-1) =41

Answer:

41

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Step-by-step explanation:

Step 1: Define

Identify

8y + 4x - (2x + 3)

x = -2

y = 6

Step 2: Evaluate

Substitute in variables:                                                                                     8(6) + 4(-2) - (2 · -2 + 3)(Parenthesis) Multiply:                                                                                      48 - 8 - (-4 + 3)(Parenthesis) Add:                                                                                            48 - 8 - (-1)Subtract:                                                                                                            41

The volume of a right cylinder is 277 cubic centimeters, and the
height is 3 centimeters (cm). What is the radius of the cylinder?

Answers

Answer:

3cm

use the formula for the volume of a cylinder

and substitute

3cm maybe is the correct answer

Can anybody help me with this problem regarding Line Integrals (Calc 3)?

Compute ∫F*dr, given the counterclockwise unit circle C : cos((pi)t), sin((pi)t), t∈[0,2] and the vector field F(x,y) = (y²,-x²)

Answers

The line integral is

[tex]\displaystyle \oint_C\mathbf F(x,y)\cdot\mathrm d\mathbf r = \int_0^2 \mathbf F(x(t),y(t))\cdot\frac{\mathrm d\mathbf r}{\mathrm dt}\,\mathrm dt \\\displaystyle= \int_0^2 (\sin^2(\pi t),-\cos^2(\pi t))\cdot(-\pi\sin(\pi t),\pi\cos(\pi t))\,\mathrm dt \\\displaystyle=-\pi\int_0^2(\sin^3(\pi t)+\cos^3(\pi t))\,\mathrm dt = \boxed{0}[/tex]

I need help I’ll give u brainlest

Answers

Answer:

216 yd³

Step-by-step explanation:

Volume of a rectangular prism

= product of the three orthogonal sides

= 6yd * 6yd * 6yd

= 216 yd³

Answer:

216

Step-by-step explanation:

:)

which of the following is the quotient of the rational expressions shown below? x/3x-1 divided by x-2/2x ?

Answers

Answer:

Below.

Step-by-step explanation:

x/3x-1 divided by x-2/2x

= x/3x-1 * 2x/x-2

= 2x^2/(3x-1)(x-2).

If we expand the denominator it is

2x^2/(3x^2-7x+2).

If m and n are two rational numbers, then m+n lies between m and n
2​

Answers

Answer:

19thuuzvdkedhddudhjdhdhfghfidhdhdhfheidhfjr9fddy6gqufgaqgxhrhrydudkydtdffyztstdtiztuytzmyrsyrststststsut0egjjefeigjeojokfzbkehfzifgihrxeudihxizhieg9zfjz9deffejfjiefeihfiefhiefhefiefh3fr3hi3jfhfhfkzdhf2ivuvdfuvuzfecfkfidyfl5a4

ANSWER ASAP PLS!!!!!

A scientist is studying the growth of a particular species of plant. He writes the following equation to show the height of the plant f(n), in cm, after n days:

f(n) = 10(1.02)n

Part A: When the scientist concluded his study, the height of the plant was approximately 11.04 cm. What is a reasonable domain to plot the growth function? (4 points)

Part B: What does the y-intercept of the graph of the function f(n) represent? (2 points)

Part C: What is the average rate of change of the function f(n) from n = 1 to n = 5, and what does it represent? (4 points)

Answers

Answer:

see below

Step-by-step explanation:

f(n) = 10(1.02)^n

Part A

Let f(n) = 11.04

11.04 = 10 * 1.02 ^n

Divide each side by 10

11.04/10 = 1.02^n

1.104 = 1.02^n

Taking the log of each side

log 1.104 = log 1.02^n

We know log a^b = b log a

log 1.104 = n log 1.02

log 1.104 / log 1.02 = n

4.99630=n

Rounding n to 5

The domain should be 0 ≤n≤5

Part B

f(n) = 10(1.02)^n

The function is in the form y =a b^x  where a is the y intercept

The y intercept is 10.  This is the value when n =0 days.

Part C

To find the average rate of change

f(5) - f(1)

-----------

5-1

f(5) = 11.04  

f(1) = 10 *1.02 =10.2

11.04 - 10.2

-----------

5-1

.84

-----

4

.21 cm per day

The average rate of growth over the 4 days is .21 cm per day

Answer:

Part A: A reasonable domain to plot the growth of the function would be: 0 < n < 5.

Part B: The y-intercept of the graph of the function f(n) represents the height of the plant in 0 days when it first began.

Part C: The average rate of change of the function from n = 1 to n = 5 is 0.84 or 0.21cm per day. It represents the amount of growth for the plant over 4 days.

, Hope this helps :)

Have a great day!!

Consider the polygon defined by the coordinates A(−3, 5), B(3, 7), C(6, −2), and D(0, −4). Which statements are correct?

A) Area of ABCD = 60 units2
B) AB = 60 units
C) CD = 40 units
D) BC = 80 units
E) Perimeter of ABCD ≈ 31.6 units

Answers

Answer:

A,C,E

Step-by-step explanation:

simplify 4-x squared ÷2x-x squared

Answers

Answer:

4-[tex]\frac{x}{2}[/tex]-[tex]x^{2}[/tex]

Step-by-step explanation:

Use technology to help you test the claim about the population mean, mu, at the given level of significance, alpha, using the given sample statistics. Assume the population is normally distributed.
Claim: μ>1220;α=0.08; σ=211.67.
Sample statistics: x=1235.91,n=300
Identify the null and alternative hypotheses and calculate the standardized test statistic.

Answers

Answer:

H0 : μ = 1220

H1 : μ > 1220

Test statistic = 1.30

Step-by-step explanation:

Sample mean, x = 1235.91

Standard deviation, σ = 211.67

Sample size, n = 300

The hypothesis :

Null ; H0 : μ = 1220

Alternative ; H1 : μ > 1220

Tbe test statistic :

(x - μ) ÷ (σ/√(n))

(1235.91 - 1220) ÷ (211.67/√(300))

15.91 / 12.220773

= 1.3018

= 1.30

he speeds (in MPH) of automobiles traveling in a city are given below:
20, 35, 42, 52, 65, 49, 24, 37, 23, 41, 50, 58
The mean speed of the cars is

Answers

Answer:

Mean speed = 41.3 mph

Step-by-step explanation:

Given that,

The speeds of an automobiles are given below:

20, 35, 42, 52, 65, 49, 24, 37, 23, 41, 50, 58

We need to find the mean speed of the cars.

Mean = sum of observations/ no. of observation

[tex]M=\dfrac{20+35+42+52+65+49+24+37+23+41+50+58}{12}\\\\M=41.3[/tex]

So, the mean speed of the cars is equal to 41.3 mph.

Rachel is driving to visit her mother, who lives 250 miles away. How long will the
drive be, round-trip, if Rachel drives at an
average speed of 40 mph?

Answers

Answer:

Time for a round trip = 12.5 hours

Step-by-step explanation:

Mother's house = 250 miles

Total distance for the round trip = 250 + 250 = 500 miles

Given speed = 40 mph

Find time .

[tex]Speed = \frac{distance }{Time }\\\\Time = \frac{distance }{speed } = \frac{500}{40} \\\\Time = 12.5 \ hours[/tex]

About 12.5 hours (hope this helps sorry if I’m wrong)

Solve the compound inequality 7x ≥ –56 and 9x < 54.

Answers

Answer: first one is x≥-8 second one is x<6

Step-by-step explanation: for the first one you divide both sides by 7 and the second won do the same except divide by 9 on each side

Hello,

7x ≥ -56

⇔ 7x / 7 ≥ -56 / 7

⇔ x ≥ -8

S = [-8 ; +∞[

9x < 54

⇔ 9x / 9 < 54 / 9

⇔ x < 6

S = ]-∞ ; 6]

:-)

How do you find the surface area

Answers

Answer:

It depends on what shape you have. Here are some formulas for different shapes.

Step-by-step explanation:

Rectangular prism: 2lw + 2lh + 2wh

Cylinder: 2 pi r² + 2 pi rh

Sphere: 4 pi r²

Cone: pi r² + pi rl

Square-based pyrimid: 1/2lp +B

I hope this helps!

In the sale, Mo buys a jacket for $63.
The original price was reduced by 25%.
Calculate the original price of the jacket.

Answers

Answer:

$84

Step-by-step explanation:

63÷3=21

63+21=84

Hope this helps! :)

A desk is on sale for $368 , which is 36% less than the regular price.
What is the regular price? PLEASE SHOW EXACTLY HOW TO DO THIS

Answers

The regular price of the desk found using the discount and the selling price is $575.

What is meant by the discount rate of an item?

Discount pricing is a form of promotional pricing strategy where the original cost of a good or service is decreased in an effort to draw more customers, move inventory, and boost sales. Consumers adore feeling as though they are getting a fantastic bargain, which is why they are lured to reduced costs. The selling price is the price at which the good or commodity has actually been sold, whereas the marked price is the cost set by the seller in accordance with market norms. The buyer claims to have received a discount when the selling price is less than the marked price.

Given,

The selling price of the desk = $368

The percentage of discount = 36%

Let the regular price be x.

then we can write the following equation,

x - 36% of x = 368

x - 0.36x = 368

0.64x = 368

x = $575

Therefore the regular price of the desk found using the discount and the selling price is $575.

To learn more about the discount rate, follow the link.

https://brainly.com/question/7459025

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Can anyone please help me

Answers

Answer:

The experiment shows the frequency of results derived from tossing a coin

Need help with this question

Answers

Answer:

cant see it

Step-by-step explanation:

just type it out

Value of 140 degree in diagrams​

Answers

Answer:

There are 360º in a circle. 140º has been allocated to one angle.

There are 360-140 = 220º left in the circle.

Step-by-step explanation:

When testing gas pumps for accuracy, fuel-quality enforcement specialists tested pumps andfound that 1304 of them were not pumping accurately (within 3.3 oz when 5 gal ispumped),and 5689 pumps were accurate. Use a 0.01 significance level to test the claimof an industryrepresentative that less than 20% of the pumps are inaccurate.

Answers

Answer:

The p-value of the test statistic from the standard normal table is 0.0017 which is less than the level of significance therefore, the null hypothesis would be rejected and it can be concluded that there is sufficient evidence to support the claim that less than 20% of the pumps are inaccurate.

Step-by-step explanation:

Here, 1304 gas pumps were not pumping accurately and 5689 pumps were accurate.

x = 1304, n = 1304 + 5689 = 6993

The level of significance = 0.01

The sample proportion of pump which is not pumping accurately can be calculated as,

The claim is that the industry representative less than 20% of the pumps are inaccurate.

The hypothesis can be constructed as:

H0: p = 0.20

H1: p < 0.20

The one-sample proportion Z test will be used.

The test statistic value can be obtained as:

[tex]Z=\frac{\hat{p}-P}{\sqrt{\frac{P(1-P))}{n}}}\\\\Z=\frac{0.186-0.20}{6993}\\\\Z=-2.927[/tex]

Mrs. Smith bought 6.2 kg of cassava and 1 kg 250 g of bananas. What is the total weight in kg? ​

Answers

Step-by-step explanation:

my answer is in the image above

fill in the blanks the 2 digit largest whole number is______​

Answers

99 is the correct answer

Find the probability

Answers

Answer:

[tex]\frac{1}{5}[/tex]

Step-by-step explanation:

Red: 2

Blue: 4

Yellow: 4

[tex]\frac{2}{10}[/tex]

[tex]\frac{2/2}{10/2}=\frac{1}{5}[/tex]

18- 3 x 2/5 - 12
Could someone help me with this?​

Answers

Answer:

I hope it helps u.......

SXB SXB SXB SXB SXB SXB SXB And And And And aand as a

A landscaper is making a garden bed in the shape of a rectangle. The length of the garden bed is 2.5 feet longer than twice the width of the bed. The area of the garden bed is 62.5 square feet. What is the perimeter of the garden bed, in feet?

Answers

Answer:

I'll setup the problem, then you can do the calculations

Step-by-step explanation:

Perimeter = 2width(W) + 2length (L)

Area = LW

L = 2.5 + 2W

LW = 62.5

substitute L in equation for area

[tex]2.5W + {2W}^{2} = 62.5 \\ \\ {2W}^{2} + 2.5 - 62.5 \\ \\ use \: quadratic \: solution \\\frac{ - b ± \sqrt{ {b}^{2} - 4ac}}{2a} [/tex]

a = 2; b = 2.5; c = 62.5

send a comment if you have a question

The perimeter of a rectangle.

P = 2 ( length + width )

The area of a rectangle.

Area = length x width

The perimeter of the rectangle shape garden bed is 32 feet.

What is a rectangle?

A rectangle is a two-dimensional shape where the length and width are different.

The area of a rectangle is given as:

Area = Length x width

We have,

A rectangular shape Landscaper:

Width = W

Length = 2.5 + W

Area = 62.5 square feet

The perimeter of a rectangle.

P = 2 ( length + width )

The area of a rectangle.

Area = length x width

Now,

Area = 62.5

length x width = 62.5

(2.5 + W)  x W = 62.5

2.5W + W² = 62.5

W² + 2.5W = 62.5

W² + 2.5W - 62.5 = 0 ______(A)

The roots of this equation (A) are:

W = 6.75 and W = -9.25 (eliminated)

Now,

Length = 2.5 + 6.75 = 9.25 feet

Width = 6.75 feet

The perimeter of the rectangle.

P = 2 ( length + width )

P = 2 x (9.25 + 6.75)

P = 2 x 16

P = 32

Thus,

The perimeter of the rectangle shape garden bed is 32 feet.

Learn more about rectangles here:

https://brainly.com/question/15019502

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she sells 6adult tickets and 5 children tickets on the first day totaling $112.50 and on the second day she sells 8adult tickets and 4 childrens tickets totaling $130. write an equation for each day and use the elimination method

Answers

Answer:

Cost of adult ticket = $12.5

Cost of child ticket = $7.5

Step-by-step explanation:

Given:

Cost of 6 adult ticket and 5 child ticket = $112.5

Cost of 8 adult ticket and 4 child ticket = $130

Find:

Equation and solution

Computation:

Assume;

Cost of adult ticket = a

Cost of child ticket = b

So,

6a + 5b = 112.5....eq1

8a + 4b = 130 ......eq2

Eq2 x 1.25

10a + 5b = 162.5 .....eq3

eq3 - eq1

4a  = 50

Cost of adult ticket = $12.5

8a + 4b = 130

8(12.5) + 4b = 130

Cost of child ticket = $7.5

The distance between two points is 10 units, if the coordinates of one of the endpoints are (4, -7), find x if the coordinates of the other endpoint are (x, 1).​

Answers

Answer:

10

Step-by-step explanation:

let the distance = d

d² = (x2-x1)² + (y2-y1)²

=>

10²= (x-4)²+(1+7)²

100 = (x-4)²+64

(x-4)²=100-64

= 36

x-4 = √36

x-4=6

x= 6+4

x= 10


The length of a rectangle should be 8 meters longer than 7 times the width. If the length must be
between 43 and 106 meters long, what are the restrictions for the width, x?

Answers

Answer:

The restrictions for x would be 14 > x > 5.

Step-by-step explanation:

Let the length of the rectangle be y and the width be x.

That being said, the equation would be as follows:

[tex]y = 7x + 8[/tex]

[tex]y - 8 = 7x[/tex]

[tex]x = \frac{y-8}{7}[/tex]

Therefore, substituting the two values of y into the equations, we would get:

[tex]x = \frac{43-8}{7}[/tex]

[tex]x = \frac{35}{7}[/tex]

[tex]x = 5[/tex]

And:

[tex]x = \frac{106-8}{7}[/tex]

[tex]x = \frac{98}{7}[/tex]

[tex]x = 14[/tex]

Therefore, x would be between 5 and 14, and the restrictions for x would be 14 > x > 5.

Hope this helped!

Which represents where f(x) = g(x)

Answers

Answer: f(2) = g(2) and f(0) = g(0)

Explanation: The graphs equal the same thing (intercept) at those x values!

If 82 pages had between 7 and 9 errors, what was the approximate total number of pages in the book?

A: 202 pages

B: 120 pages

C: 68 pages

D: 56 pages

Answers

Answer:

120 pages

Step-by-step explanation:

The mean number of error per page = 8 ; Standard deviation = 1

Given that :

82 pages has between 7 and 9 errors per page ;

Using the empirical rule :

7 = 8 - 1 = 1 standard deviation below the mean

9 = 8 + 1 = 1 standard deviation above the mean

1 standard deviation from the mean = 68%

Hence, 82 pages = 68%

Approximate total pages :

68% = 82

100% = total pages, x

0.68 = 82

1 = x

0.68x = 82

x = 82 / 0.68

x = 120.588

Hence, total number of pages is 120 pages

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