In a lab experiment, the decay of a radioactive isotope is being observed. At the beginning of the first day of the experiment the mass of the substance was 500 grams and mass was decreasing by 8% per day. Determine the mass of the radioactive sample at the beginning of the 13th day of the experiment. Round to the nearest tenth (if necessary).

Answers

Answer 1

Using an exponential function, it is found that the mass of the radioactive sample at the beginning of the 13th day of the experiment was of 169.1 mg.

What is an exponential function?

A decaying exponential function is modeled by:

[tex]A(t) = A(0)(1 - r)^t[/tex]

In which:

A(0) is the initial value.r is the decay rate, as a decimal.

At the beginning of the first day of the experiment the mass of the substance was 500 grams and mass was decreasing by 8% per day, hence A(0) = 500, r = 0.08, and the equation is given by:

[tex]A(t) = A(0)(1 - r)^t[/tex]

[tex]A(t) = 500(1 - 0.08)^t[/tex]

[tex]A(t) = 500(0.92)^t[/tex]

At the 13th day, the mass is given by:

[tex]A(13) = 500(0.92)^{13} = 169.1[/tex]

More can be learned about exponential functions at https://brainly.com/question/25537936


Related Questions

Find the volume of the pyramid.

A) 22 cm3
B) 264 cm3
C) 132 cm3
D) 44 cm3

Answers

264 cm3.
Length * width * height gives the volume of a shape.

Suppose a city with population 100,000 has been growing at a rate of 5% per year. If this rate​ continues, find the population of this city in 21 years.

Answers

Answer:

205,000

Step-by-step explanation:

(100,000*0.05) *21 +100,000

How do we do this? The sub gave us the wrong work and isn’t explaining it! Help please!!!

Answers

Answer:

1) 18b - 3c - 10

2) [tex]1\frac{3}{4}[/tex]g + 7

3) 0.3y

4) -4n - 5

Step-by-step explanation:

1) 16b + 5c - 10 - 8c + 2b

like terms: 16b + 2b = 18b

like terms: 5c - 8c = -3c

like terms: -10

simplified: 18b - 3c - 10

____________

2) 1/2g + 2g - 3/4 g + 7

like terms: 1/2g + 2g - 3/4g

2 1/2 - 3/4

improper fraction > 5/2 > same denom > 10/4

10/4 - 3/4 = 7/4 > mixed number> 1 3/4g

like terms: +7

simplified: 1 3/4g + 7

____________

3) -0.9y + 4.4y - 3.2y

like terms:  -0.9y + 4.4y - 3.2y

simplified: 0.3y

____________

4) 4 - 8n + 7n - 3n - 9

like terms: -8n + 7n - 3n = -4n

like terms: 4 - 9 = -5

simplified: -4n - 5

____________

Part A
Which angles are congruent to ∠5 ? Select all that apply.
∠1
∠2
∠3
∠4
∠6
∠7
Part B
I m∠6 = 85° what is the measure of ∠3?

m∠3 =
°

Answers

part a: 1,3,5,7

part b: i’m not sure

last question i have to ask ‘calculate the area of the shaded space’ please and thank you.

Answers

Answer:

21.5 square m

Step-by-step explanation:

You find the area of the shaded space by finding the area of the square and the removing the area of the circle.

The area for the square is 10x10=100.

All you have to do is follow the formula, (3.14)r^2. However, the 10 is NOT the diameter! The radius is half of the diameter. So, it's 3.14x5x5, which is 3.14x25=78.5.

Then, you can do 100-78.5=21.5

Answer the one you would like!

Answers

first pic no 13

sec no 14

third no 15

shjdidifjie

F(x) =3x+8 find the inverse of f(x)

Answers

Answer:

Step-by-step explanation:

Hi!

To find the inverse, first we express your function as:

y = 3x - 8

Then, we interchange x and y variables:

x = 3y - 8

From there, we isolate y:

x + 8 = 3y

x/3 + 8/3 = y

Then, the inverse, g(x) = (x+8)/3.

We can check this by getting g(f(x)):

(f(x) + 8)/3 = (3x - 8 + 8)/3 = 3x /3 = x.

This is correct by the definition of the inverse function.

You can also think about the inverse as a "reverse function", so for example, in f(x) = 3x-8, x is multiplied by 3, then 8 is subtracted from it.

If we are to go from f(x) to x, we first add 8 (to reverse the subtraction), then divide by 3 (to reverse the multiplication).

This means g(y) = (y+8)/3, the same answer.

Hope this helps!

Which value of x makes the following equation true? 2(x + 7) = x + 19 OA. 5 OB. 12 O C. 19 OD -2​

Answers

2(x + 7) = x + 19

Use distributive property on left side;

2x + 14 = x + 19

Subtract 14 from both sides:

2x = x + 5

Subtract 1 x from both sides:

X = 5

The probability that the sample will accurately represent the target group within the margin of error is called the Group of answer choices confidence level. polling bias. margin of error. random sample.

Answers

Answer:

What is the probability of a sample mean?

The Probability of a Sample Mean The Probability of a Sample Mean We saw in the previous section that if we take samples, the distribution of the sample means will be approximately normal. This will hold true even when the underlying population is not normally distributed, provided we take samples of n=30 or greater.p-by-step

which statement is true about credit cards?

Answers

Answer:

it doesnt say any statement at all can you add them

CAN SOMEONE HELP ME PLSSSSSS I ASKED THIS LIKE 3 TIMES BUT NO ONE ANSWERED.THABKYOU!
Determine the area of the park that is not covered by the wading pool.

Answers

Answer:

19.63 m^2

Step-by-step explanation:

This is an Area=pi r^2 equation so it would be 3.14*2.5^2

What is the area of the triangle shown below ?3.7mm 4.8mm

Answers

I can’t answer because I don’t have the picture of the triangle

The train was scheduled to arrive at 5:10 p.m. However٫it was delayed for 25 minutes. What time was it when the train arrived?

Answers

Answer:
4:45

if the train was schedules to arrive at 5:10, you must subtract 25 minutes (the delay) to get your answer: 4:45

Answer:

5:35 p.m.

Step-by-step explanation: Just add 25 to 5:10

Using the function f(x) = 32 * (3/4)z, evaluate the following mentally.
f(3) =

Answers

Answer:

I also need help with this I'm new to this app so id

is 47°, what is the measure of Z3?


Ο Α. 1536
O B. 43
O C. 133
O D. 47°

Answers

Answer:

<3=C. 133

Step-by-step explanation:

Well, angle 2 and angle 3 are corrisponding angles, meaning that they are on the same line, and a line is always equal to 180, and 47 degrees is a part of that line, and you need the other part of that line for angle 3, so you simply subtract 180-47=133 degrees

What is 10+10-4x3=??
I will give a free brainliest to the first person to respond to this question :)

Answers

Answer:

8

Step-by-step explanation:

PEMDAS

Parentheses

Exponents

Multiplication

Division

Addition

Subtraction

[tex]10 + 10 - 4 \times 3 \\ 4 \times 3 = 12 \\ 10 + 10 - 12 \\ 10 + 10 = 20 \\ 20 - 12 = 8[/tex]

Answer:

8

Step-by-step explanation:

4x3 first = 12

then just do left to right

10+10=20

20-12=8

Round 19525 to the nearest hundred​

Answers

19500 because the 5 is in the 100 Collum so you round the 2 down keeping it as a 5

Answer:19,500

Step-by-step explanation: Yw.


A tank that holds 120 gallons is leaking at a rate of
gallon per hour. Wri
an expression that represents the amount of gallons left in the tank after h
number of hours.

Answers

Answer:h=120 - (120•1/4)

Step-by-step explanation:

Question 7 of 10
Which situation involves a conditional probability?
O A. The probability that you make a second free throw given that you
made the first free throw
B. The probability that you are given a book for your birthday
O C. The probability that you make two free throws in basketball
D. The probability that you roll a 6 on a number cube
SUBMIT

Answers

A) The probability that you make a second free throw given that you made the first free throw

What's the volume of this container (QUICK)

Answers

Answer:

1468 in^3

Step-by-step explanation:

Multiply all of the larger box dimensions

10 * 10 * 15 = 1500  in^3

subtract the smaller box cut out corner

2 * 4 * 4 =  32

1500 - 32 = 1468 in^3

What is the slope of the line in this graph? please help urgent

Answers

Answer:

  (b)  5/7

Step-by-step explanation:

When determining slope from a graph, it is convenient to locate points on the graph where it crosses grid lines. This graph crosses the origin, and the point (7, 5). The slope is found by counting grid squares or by the slope formula ...

  m = (y2 -y1)/(x2 -x1)

  m = (5 -0) /(7 -0) = 5/7 . . . . . . . . . using points (0, 0) and (7, 5)

The slope of the line is 5/7.

A movie theater charges $10.50 per ticket and $5per bucket of popcorn. You never buy the popcorn because you think it's too expensive.
Is the total price you pay proportional to the number of tickets you buy?
Choose 1 answer:

(Choice A)
A
Yes

(Choice B)
B
No

Answers

Yes they are proportional

Answer:

A- yes

Step-by-step explanation:

If you never buy the popcorn because you think that it is too expensive then the only thing you are paying for is the tickets therefore the price you pay is proportional to the number of tickets you buy.

Which of the following points is in the solution set of y < x^2 - 2x - 8?
(4, 0)
(-2, -1)
(0, -2)

Answers

Answer:

(4,0)

Step-by-step explanation:

Out of the given answers (4,0) would be correct

Evaluate the formula for the perimeter of a rectangle to solve the problem. Then check all that apply.
ANSWERS:
First, write the formula for the perimeter of a rectangle: P = 2l + 2w.
Next, use parentheses when you substitute 50 for l and 25 for w.
After multiplying, add 100 and 50.
The school needs 5,000 meters of fencing.
The school needs 150 meters of fencing.

Answers

1. 2(8x – 1) + 2(2x + 4)

2. 16x – 2 + 4x + 8

3. (20x + 6)

Step-by-step explanation:

The perimeter of the rectangle with length 8x - 1 and width 10x + 3 is 20x + 6

The formula for calculating the perimeter of a rectangle is expressed as:

P = 2( l + w)

Given the following parameters

length l = 8x - 1

width w = 2x + 4

Substitute the expressions for the length and width into the formula;

P = 2(8x - 1 + 2x + 4)

P = 2(10x + 3)

Distribute 2 over each term in the parenthesis

P = 2(10x) + 2(3)

P = 20x + 6

Hence the perimeter of the rectangle with length 8x - 1 and width 10x + 3 is 20x + 6

if i help please give brainly

Answer:

below

Step-by-step explanation:

A B C E

all of them but D

Out of 40 girls, 10 girls can cook
well. What fraction of girls can
cook well?

Answers

Answer:

1/4

Step-by-step explanation:

10 girls can cook well out of a total of 40 girls.

this means 10/40 girls can cook well, simplified fraction by dividing top and bottom by 10, 1/4 girls can cook well

Answer:

1/4

Step-by-step explanation:

When you simplify 10/40 you get 1/4

pls help me


What is the volume of the figure?

Answers

Answer:

V = 76 ft³

Step-by-step explanation:

We can find the volume of the figure by finding the sum of volume of the small rectangular prism and big rectangular prism.

V of a rectangular prism = length*hight* width

V = V (big rectangular prism) + V (small rectangular prism)

V = (8·4·2) +(3·2·2)

V = 64 + 12

V = 76 ft³

i do not know this answer, i need help

Answers

Answer:

18 kilometers

Step-by-step explanation:

if you know the perimeter, then all you have to do is add up what you have, 10+7=17 and then subtract it giving you the bits that you dont know, so 35-17=18 kilometers.

Answer:

s = 9 Km

Step-by-step explanation:

the perimeter is the sum of the 4 sides

given perimeter = 35 , then

10 + 7 + s + s = 35

17 + 2s = 35 ( subtract 17 from both sides )

2s = 18 ( divide both sides by 2 )

s = 9 Km

The means and mean absolute deviations of sidney’s and phil’s grades are shown in the table below. means and mean absolute deviations of sidney’s and phil’s grades sidney phil mean 82 78 mean absolute deviation 3.28 3.96 which expression represents the ratio of the difference of the two means to sidney’s mean absolute deviation? startfraction 82 over 3.28 endfraction startfraction 4 over 3.28 endfraction startfraction 4 over 0.68 endfraction startfraction 82 over 0.68 endfraction

Answers

The expression that represents the ratio of the difference of the two means to Sidney’s mean absolute deviation is given by: Option B: 4/3.28

What is mean absolute deviation?

Mean absolute deviation is the average of the absolute deviation of each observation from their mean, for a considered set of observations.

For this case, the table of mean and mean absolute deviation is given as:

[tex]\begin{array}{ccc}&Mean&M.A.D.\\\text{Sidney}&82&3.28\\\text{Phill}&78&3.96\end{array}[/tex]

(M.A.D refers to Mean Absolute Deviation).

So, difference in their mean is 82 - 78 = 4

Absolute deviation  for Sidney is 3.28

Thier ratio is: 4/3.28

Thus, the expression that represents the ratio of the difference of the two means to Sidney’s mean absolute deviation is given by: Option B: 4/3.28

Learn more about ratio here:

https://brainly.com/question/12106245

Answer:

Option B: 4/3.28

Step-by-step explanation:

7. A spherical balloon has a circumference of 25 cm.
a.) What is the approximate surface area of the balloon to the nearest square centimeter?
b.) What is the approximate volume of the balloon to the nearest cubic centimeter?

Answers

Answer:

surface area of the balloon is 199 cm^2

Use the following system of linear equations to do the three tasks below.
x = y +3
Y=-4x-3
• Part A: Solve the linear system of equations by graphing.
• Part B: Use substitution to solve the linear system of equations.
• Part C: Use addition to solve the linear system of equations.
In your final answer, include all of your work, the graph of the equations and the solution.

Answers

Step-by-step explanation:

where the is y,you put the value of y 4x-3 and where the is x,put the value of x (y+3)

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