20) After 8 hours, half of a 16-gram sample of a radioactive element remains. Find the constant k for this element for t hours, then use y=ne^-kt to write the equation for modeling it’s exponential decay
- please help me

Answers

Answer 1

Answer:

k = 0.086

Step-by-step explanation:

We have the equation

y=ne^(-kt)

where y is the amount of radioactive material after t hours, n is the initial amount of radioactive material, and k is some constant.

We know the following data:

t: 8 hoursy = n/2 (half of a radioactive element remains)

Replacing into the equation and solving for k:

[tex]y=ne^{-kt}[/tex]

[tex]\frac{n}{2}=ne^{-k8}[/tex]

[tex]0.5=e^{-k8}[/tex]

[tex]ln(0.5)=ln(e^{-k8})[/tex]

[tex]ln(0.5)=-k8ln(e)[/tex]

[tex]\frac{ln(0.5)}{-8}=k[/tex]

[tex]\frac{ln(0.5)}{-8}=k[/tex]

[tex]k = 0.086[/tex]


Related Questions

Which equation represents h(x)?

Answers

Answer: The second choice: h(x) = (f(x))(g(x))

Step-by-step explanation:

f(x) = -15

g(x) = 15

h(x) = -225

-15 * 15 = -225

Therefore, h(x) is the distribution of f(x) and g(x).

each ice cream cone cost $100. Students get 5 1/2 and seniors get 7 1/2. how much more does seniors get?

Answers

Answer:

2

Step-by-step explanation:

7 1/2 - 5 1/2

7.5 - 5.5

2

Express the recurring decimal 0.1555555555... as a fraction give answer in its simplest form

Answers

in it's simplest form it's 0.1555555555

What is the median of the data
represented in the box plot below?
25
35
45
55

Answers

Answer:

40

Step-by-step explanation:

-To find the median with an odd set of numbers

put the numbers in chronological orderfind the number in the middle and that is your answer

-To find the median with a even set of numbers

put the numbers in chronological orderfind the average of two numbers in the middle (to do so:add the 2 numbers in the middledivide that number by 2and that's your answer

The numerical coefficient in "6m" is:

Answers

The numeral coefficient is the number ( the one that we know)- so its 6

2 Points
The table shows the number of weeks of vacation employees receive each
year, based on the number of years they have been employed. What does
(15) = 5 mean in terms of the problem?
Years of
Service
Weeks of
Vacation
1
2.
1
2
5
10
15
20
30
3
4
5
6
8
O A. There are 5 workers who have 15 years of service each
OB. A worker took 5 weeks of vacation in 15 years.
O C. A worker with 15 years of service gets 5 weeks of vacation each
year
OD. A worker with 5 years of service gets 15 weeks of vacation each
year
SUBMIT

Answers

The answer to your question is 3

Can you guys help and put these in order?

Answers

-3, -2.5, -3/4, 1/4, 3.1, 16/5, 6. I can’t see the other numbers, so it’s just these

Your fixed expenses are $1,035.65/month and are 36% of your
realized income. Use proportions to compute the realized
income on your budget.
/month

Answers

Answer:

Your realized income is an estamated $2876.81 per month

Step-by-step explanation:

36% can be translated to decimal form as 0.36, when multiplying 2876.81 times 0.36 you get 1035.65, making your estimated Total monthly income $2876.81

Solve for x: x + 18 = -37 A. x = -55 B. x = -18 C. x = -19 D. x = 14

Answers

-55+18= -37 so the answer is A

Answer:

A. x= -55

Step-by-step explanation:

got it

Which of the following questions describes the equation 4n = -24?

What number, when multiplied by -24, equals 4?
What number, when divided by 4, equals -24?
What number, when multiplied by 4, equals -24?
What number, when divided by -24, equals 4?

Answers

pretty sure it’s the third one

Pleaseeeeee HELP!!! ASAP

Answers

Answer:

I think its D

Harry bought a sweater that only cost $5 when it normally costs $35. What percent was the discount? Provide an explanation. A. 16.7% B. 14.3% C. 30.0% D. 85.7%

Answers

Answer:

D. 85.7%

Step-by-step explanation:

its figuring out the percentage decrease

so you would go

35-5= 30

30/35 x 100 = 85.7

Answer:

Step-by-step explanation:

Discount = 35 - 5 = 30

Percentage of discount = (30/35) * 100

                                       = 85.7 %

Find the value of n.
n = -1.-7

Answers

Answer:

n = 7

Step-by-step explanation:

n = (-1) x (-7)

Simplify:

When two minus signs appear in the product of two numbers, you can cancel them out.

Therefore:

n = (1) x (7) = 7

Hope this helps!

:)

Jayne polled 50 students about their preferred after-school sport and then recorded the data in the table below. Which sport is more popular?

A. You can use a relative frequency table to examine how data sets are related by comparing percentages.

B. Row and column relative frequency tables tell you the same information as total relative frequency tables.

C. A column relative frequency table helps compare data in two different rows.

D. In a column two-way relative frequency table, each column totals 100%.

Answers

Step-by-step explanation:

D. In a column two-way relative frequency table, each column totals 100%.

A baker is making bread rolls. He divides his dough into 8 equal pieces. He then cuts each one of these pieces into three, each of which is a single bread roll. He sells the rolls in bags of 4. original dough is in one bag of rolls give your answer in its simplest form

Answers

Answer:

6 bags

Step-by-step explanation:

8x3=24

24/4=6

Find the vertex of the parabola.
f(x) = 5x2 - 30x +49
a. (3,0)
b. (3,4)
C. (4,0)
d. (4,3)

Answers

Answer:

B.

Step-by-step explanation:

because the vertex of parabola is f(x)

What is the value of the expression?

Negative 16 + 12

Answers

Answer:

-4

Step-by-step explanation:

-16 + 12

When the signs are different we subtract the smaller from the larger and take the sign of the larger

16-12 = 4

The larger number has a sign of negative

-4

Answer:

b

Step-by-step explanation:

ur mom

GIVING BRAINLIEST EASY QUESTION!!!!!!!!!!!!!!
The coordinate grid shows three points P, Q, and R:

A four-quadrant coordinate grid from negative 10 to positive 10 in increments of 2 is drawn. Point P is plotted on the ordered pair negative 2, negative 8. Point Q is plotted on the ordered pair negative 4, negative 2. Point R is plotted on the ordered pair 8, negative 2.

The distance between Q and R is ______ units.

Answers

Answer:

The answer is 10! :)

(Just realized this was posted in 2020, but whatever)

i need help please !

Answers

Answer:

A. Yes, because it passes the vertical line test.

Step-by-step explanation:

The vertical line test requires you to draw a vertical line through any part of the graph. If the line intersects the graph at only one point, the graph represents a function. This graph passes that test. As for the other answer choices, the "horizontal line test" is not a way to see if a graph represents a function. I hope this helps :))

Answer:

A. Yes, because it passes the vertical line test.

Step-by-step explanation:

The vertical line test states that you can draw a line parallel to the y-axis for any chosen value of x. If the vertical line you drew intersects the graph more than once for any value of x then the graph is not the graph of a function. In this case, the line doesn't intersect the graph more than once.

^ this week, The sparkling water was 4 for $5 , the regular was $1.69

Answers

This week you paid $1.25 each because they were on sale for four for $5.

Events A and B are overlapping.

P(A) = 4/11; P(B) = 3/11, P(A and B) =2/11 .

Find P(A or B).

Answers

Answer:

5/11

Step-by-step explanation:

Since the events are overlapping...

P(A or B) = P(A) + P(B) - P(A and B)

P(A) = 4/11

P(B) = 3/11

P(A and B) = 2/11

P(A or B)  = 4/11 + 3/11 - 2/11

P(A or B)  = 5/11

Answer:

5/11

Step-by-step explanation:

what is 2 with an exponent of negative 2 equal to?

Answers

Answer:

So since we have 2^-2 We can do 1/2^2  = 0.25

So if you have y^-x = 1/y^x

Answer:

1/4

Step-by-step explanation:

negative exponent rule says a ⁻ⁿ = 1/ aⁿ so:

2⁻² =1/2² = 1/4

What is the solution to the system of equations below?
2x + 3y = 6
x - 3y = 9

Answers

Step-by-step explanation:

2x + 3y =  6             3x = 15                    5 - 3y = 9

x   - 3y  = 9               x = 15/3 = 5            y = 9 - 5/-3 = -4/3

3x        = 15

What is 25% of $4007

Answers

Answer:

$1001.75

Step-by-step explanation:

Do 4007 x 0. 25 on a calculator

Your mom bought a new couch on sale for $840. If the sale was 30%, what was the Original Price?

Answers

Answer:

1200$

Step-by-step explanation:

(840/(100-30))*100

(840/70)*100

12*100

1200

PLEASE JUST GIVE ME THE VOLUME! THE AREA OF THE SECTION IS 546! PLEASE ANSWER ASAP!!!!!!!

Answers

Answer:

3360

Step-by-step explanation:

By the Pythagorean Theorem, you know that:

[tex]C_1B_1=\sqrt{29^2-20^2}=\sqrt{841-400}=\sqrt{441}=21[/tex]

This means that the area of the triangular base is [tex]\dfrac{21\cdot 20}{2}=210[/tex]. Multiplying this by the height of the pyramid and dividing by 3, you get a volume of 3360. Hope this helps!

Determine which equation below can be solved to find the value of Angle
A. *

Answers

Answer:

i believe the correct answer is x+90+63=180

Step-by-step explanation:

Answer:

x + 90 + 63 = 180

Step-by-step explanation:

We do not have the value for angle B so we have to assume that B plus the 45 is 90. using this info we can see that A + 90 + 63 is equal to the line, which is 180(as all lines are). We can then get the equation x + 90 + 63 = 180

Rick is deciding what to wear to school. He has two different shirts, two different pants and two different pairs of shoes to choose from. How many different outfit combinations does he have to choose from?

Answers

Answer:

a total of 8 outfits

Step-by-step explanation:

shoes: L1, L2

shirts: S1, S2

pants: P1, P2

1: S1, P1, L1

2: S1, P1, L2

3: S1, P2, L1

4: S1, P2, L2

5: S2, P1, L1

6: S2, P1, L2

7: S2, P2, L1

8: S2, P2, L2

I hope that makes sense, since I couldnt figure out how to show the diagram.

The function g is defined by g(x) =
x + 5
4x + 3
Find g (5a)

Answers

The answer is 23 4(5) + 3 = 23

circumference in terms of pi does anyone know this?

Answers

Answer:

15 pi

Step-by-step explanation:

Answer:

15π cm

Step-by-step explanation:

The circumference of a circle can be found using the following formula:

c= d* π

We know that the diameter of the circle is 15 centimeters. Therefore, we can substitute 15 cm in for d

c= 15 cm * π

Since we are told to find the circumference in terms of pi, the answer is left as:

c= 15*π  cm

c= 15π cm

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