8. A substance has a half life of 2.347 minutes.
a. If the initial amount of the substance was 110.4 grams, how many half-lives will have passed
before the substance decays to 6.9 grams.
b. What is the total time of the decay?

Answers

Answer 1

Answer:

a.) 4 half lives have passed

b) 9.388 minutes

Step-by-step explanation:

Formula for exponential growth / decay is given as:

[tex]A=A_0b^{\frac{t}{c}}[/tex]

Where [tex]A[/tex] is the final population

[tex]A_0[/tex] is the initial population

[tex]b[/tex] is the growth factor

[tex]c[/tex] is the time taken for the growth 'b'

[tex]t[/tex] is the amount of time

Here, we are given that:

[tex]A[/tex] = 6. 9 grams

[tex]A_0[/tex] = 110.4 grams

[tex]b = \dfrac{1}{2}[/tex]

[tex]c = 2.347[/tex] min

To find:

a.) Number of half lives taken for the decay.

b.) Total time in the decay.

Solution:

a.) Number of half lives taken for the decay is nothing but equal to [tex]\frac{t}{c}[/tex].

Putting the values in the formula, we get:

[tex]6.9=110.4\times \frac{1}2^{\frac{t}{c}}\\\Rightarrow 6.9=110.4\times 0.5^{\frac{t}{c}}\\\Rightarrow 0.0625=0.5^{\frac{t}{c}}\\\Rightarrow \dfrac{t}{c} =4[/tex]

Therefore, the answer is:

4 half lives have passed.

b.) Total time of decay. We have to find the value of [tex]t[/tex] here.

From answer of part a.):

[tex]\dfrac{t}{c} =4\\\Rightarrow \dfrac{t}{2.347} =4\\\Rightarrow t =\bold{9.388\ min}[/tex]


Related Questions

Un banco de México es comprado por otra institución de origen español. El nuevo director, decide fusionar la operación entre ambas instituciones donde se aprovisionen servicios de internet desde España a México. Para lograr lo anterior, ¿qué debe plantear el director como proyecto para unir ambas operaciones?

Answers

Question:

A bank in Mexico is bought by another institution of Spanish origin. The new director decides to merge the operation between both institutions where internet services are provided from Spain to Mexico. To achieve this, what should the director propose as a project to unite both operations?

My mom translated this for me and I am writing the reply with Google Translate sorry if it sucks.

Ésta es una pregunta muy específica. Creo que dependería de la preferencia del director y de los fondos.

88) 4 times a number decreased by 8 equals 40
A) x=80 B) x = 40 C) x=8
D) x = 12

Answers

D=12
Because if you write down the equation 4x-8=40 and plug in 12. 4 times 12 is 48
. 48-8 equals 40

How much sparkling water would you need to make 100 quarts of sparkling grape juice? (Recipe for sparkling grape juice calls for 1 1/2 quarts of sparkling water and 3/4 quarts of grape juice)

Answers

Answer:

66.6666

Step-by-step explanation

This is the answer because I found it up here and I got the answer right.

what is the equation of a line perpendicular to line with equation 2x-5y=5

Answers

Answer:

its -5

Step-by-step explanation:

89.36 in word form i have it in expanded form not word form though pls help ??????????????????????????????????????????????????????????????????????///

Answers

Answer:

eighty-nine and thirty-six hundredths

or, simpler:

eighty-nine point thirty-six

or, even simpler:

eighty-nine point three six

Answer:

eighty-nine and thirty-six hundredths

Step-by-step explanation:

Which equation correctly shows the relationship between the numbers 6,560 and 656?

Answers

Answer:

656×1000

Step-by-step explanation:

Assume that SAT scores are normally distributed with mean 1518 and standard deviation 325. Round your answers to 4 decimal placesa. If 100 SAT scores are randomly selected, find the probability that they have a mean less than 1500.b. If 64 SAT scores are randomly selected, find the probability that they have a mean greater than 1600c. If 25 SAT scores are randomly selected, find the probability that they have a mean between 1550 and 1575d. If 16 SAT scores are randomly selected, find the probability that they have a mean between 1440 and 1480.e. In part c and part d, why can the central limit theorem be used even though the sample size does not exceed 30?

Answers

Answer:

a. 0.2898

b. 0.0218

c. 0.1210

d. 0.1515

e. This is because the population is normally distributed.

Step-by-step explanation:

Assume that SAT scores are normally distributed with mean 1518 and standard deviation 325. Round your answers to 4 decimal places

We are using the z score formula when random samples

This is given as:

z = (x-μ)/σ/√n

where x is the raw score

μ is the population mean

σ is the population standard deviation.

n is the random number of samples

a.If 100 SAT scores are randomly selected, find the probability that they have a mean less than 1500.

For x = 1500, n = 100

z = 1500 - 1518/325/√100

z = -18/325/10

z = -18/32.5

z = -0.55385

Probability value from Z-Table:

P(x<1500) = 0.28984

Approximately = 0.2898

b. If 64 SAT scores are randomly selected, find the probability that they have a mean greater than 1600

For x = 1600, n = 64

= z = 1600 - 1518/325/√64.

z= 1600 - 1518 /325/8

z = 2.01846

Probability value from Z-Table:

P(x<1600) = 0.97823

P(x>1600) = 1 - P(x<1600) = 0.021772

Approximately = 0.0218

c. If 25 SAT scores are randomly selected, find the probability that they have a mean between 1550 and 1575

For x = 1550, n = 25

z = 1550 - 1518/325/√25

z = 1550 - 1518/325/5

z = 1550 - 1518/65

= 0.49231

Probability value from Z-Table:

P(x = 1550) = 0.68875

For x = 1575 , n = 25

z = 1575 - 1518/325/√25

z = 1575 - 1518/325/5

z = 1575 - 1518/65

z = 0.87692

Probability value from Z-Table:

P(x=1575) = 0.80974

The probability that they have a mean between 1550 and 1575

P(x = 1575) - P(x = 1550)

= 0.80974 - 0.68875

= 0.12099

Approximately = 0.1210

d. If 16 SAT scores are randomly selected, find the probability that they have a mean between 1440 and 1480

For x = 1440, n = 16

z = 1440 - 1518/325/√16

= -0.96

Probability value from Z-Table:

P(x = 1440) = 0.16853

For x = 1480, n = 16

z = 1480 - 1518/325/√16

=-0.46769

Probability value from Z-Table:

P(x = 1480) = 0.32

The probability that they have a mean between 1440 and 1480

P(x = 1480) - P(x = 1440)

= 0.32 - 0.16853

= 0.15147

Approximately = 0.1515

e. In part c and part d, why can the central limit theorem be used even though the sample size does not exceed 30?

The central theorem can be used even though the sample size does not exceed 30 because the population is normally distributed.

The following is a set of hypotheses, some information from one or more samples, and a standard error from a randomization distribution. Test H0 : p=0.28 vs Ha : p<0.28 when the sample has n=800, and p^=0.217 with SE=0.01.

Required:
Find the value of the standardized z-test statistic.

Answers

Answer:

Z = -6.3

Step-by-step explanation:

Given that:

[tex]\mathbf{H_o :p= 0.28}[/tex]

[tex]\mathbf{H_o :p < 0.28}[/tex]

Since the alternative hypothesis is less than 0.28, then this is a left-tailed hypothesis.

Sample sixe n = 800

[tex]\hat p[/tex] = 0.217

The standard error [tex]S.E(p) = \sqrt{\dfrac{p(1-p)}{n}}[/tex]

[tex]S.E(p) = \sqrt{\dfrac{0.28(1-0.28)}{800}}[/tex]

[tex]S.E(p) \simeq0.015[/tex]

Since this is a single proportional test, the test statistics can be computed as:

[tex]Z = \dfrac{\hat p - p}{\sqrt{\dfrac{p(1-p)}{n}}}[/tex]

[tex]Z = \dfrac{0.217- 0.28}{0.01}[/tex]

Z = -6.3

Daniel bought a package of 12 water bottles for $6. Write an equation that relates the cost, c, of a package of water bottles to the number of bottles, b, in the package?

Answers

Answer:

c = 2b

Step-by-step explanation:

First, find the cost of one water bottle by dividing the total cost by the number of water bottles:

12/6

= 2

Then, set up an equation.

2b, where b is the number of bottles, represents the cost of the package of water bottles.

Set this equal to c, the cost, to create the equation.

c = 2b is the equation relating the cost to the number of bottles

How much does Jimmy earn each week, and
how much does he save by week 4?
A. Jimmy earns $3 each week, and he has $12 by
week 4.
B. Jimmy earns $3 each week, and he has $10 by
week 4.
C. Jimmy earns $6 each week, and he has $12 by
week 4.
D. Jimmy earns $6 each week, and he has $10 by
week 4.

Answers

Answer:

we need more info to answer this question

Answer:

A.

Step-by-step explanation:

12 divided by 4 equals 3. So if he gets 3 dollars a week by the fourth week he should have 12 dollars. It could also be 4 times 3 equals 12.

Please help im stuck

Answers

Answer:

B

Step-by-step explanation:

substitution because

if m∠3=m∠7, and m∠7=m∠6 you can substitute

m∠7 to m∠3 and get m∠3=m∠6

Which of the following ratios is not equivalent to 2:10
A.1/5
B.2/5
C.4/20
D.6/30

Answers

Answer:

D because 6/30 is not the same as 2:10

Answer:

2/5 is not equibalent to 2:10

Step-by-step explanation:

2:10

1/5 × 2 = 2/10

2/5 × 2 = 4/10

4/20÷2 = 2/10

6/30÷3 = 2/10

2. An inaccurate clock loses
3.
minutes every 8 hours. How much time will the clock lose in one
week?

Answers

Answer: If it loses 3 minutes every 8 hrs than it loses 9 minutes every day. 9*7=63, it will lose 63 minutes in one week.

Solve for x in the expression:
3 + 2x + 5 =0​

Answers

x=-4
3+5 = 8
2x+8=0
2x = -8
x=-4

Answer:

x= -4

Step-by-step explanation:

3 + 2x + 5 = 0

8 + 2x = 0

2x = -8

2x/2 = -8/2

x= -4

Answer This math question and ill give brainliest

Answers

Answer:

16 miles

Step-by-step explanation:

there are 8 units between the points each unit is 2 miles so 8*2= 16

What were the coordinates of point B after being translated 4 units left

Answers

Answer: B' (x-4,y)

Step-by-step explanation: A figure which is moved from one location to antoher, without changing its size, shape or orientation, is a figure that went through translation.

So, when a point is translated, it means it changed its position.

Point B has x- and y-coordinates: B(x,y)

Point B' after being translated 4 units left means:

(x,y) → (x-4,y)

In other words, translated point B has coordinates

B(x-4, y)

Because moving left is saying the point is moving towards the negative "side" of the x-axis.

Answer Choices:

A) (-6, -1)

B) (6, -1)

C) (-6, 1)

Help Number three please!!!

Answers

Step-by-step explanation:

108-ambulance

100- police

1098-child laber

i need to know the answer to this is radical form

Answers

The answer is the last on 12

Which graph shows a proportional relationship between the number of hours of renting a canoe and the total amount spent to rent the canoe?

Answers

Answer:

Uh pick a graph that is straight line and passes through 0

Step-by-step explanation:

You don't have screenshot

Answer:

This would be simaler to the answer

Step-by-step explanation:

A graph is shown. The values on the x axis are 0, 2, 4, 6, 8, 10. The values on the y axis are 0, 18, 36, 54, 72, and 90. Points are shown on ordered pairs 0, 0 and 2, 18 and 4, 36 and 6, 54 and 8, 72. These points are connected by a line. The label on the x axis is Number of Hours. The title on the y axis is Total Amount in dollars.

BLANK% of 50 shirts is 2 shirts.

Answers

Answer:

4%

Step-by-step explanation:

2/50 is 4....I believe.

Solve for g.

g + (-5) = 27

Answers

g=32
you add 5 to 27 since it is a negative. and then 32-5=27

answer: g=32 u should simplify

b. Multiply (3 x - 1) by (x + 1)​

Answers

Answer:

(3x - 1)(x + 1) = 3x² + 2x - 1

Step-by-step explanation:

[tex] \rm \longrightarrow (3x - 1)(x + 1) \\ \\ \rm \longrightarrow 3x(x + 1) - 1(x + 1) \\ \\ \rm \longrightarrow (3x)(x) + (3x)(1) + ( - 1)(x) + ( - 1)(1) \\ \\ \rm \longrightarrow 3 {x}^{2} + 3x + ( - x ) + ( - 1) \\ \\ \rm \longrightarrow 3 {x}^{2} + 3x - x - 1 \\ \\ \rm \longrightarrow 3 {x}^{2} + 2x - 1[/tex]

Answer:

(3x - 1)(x + 1) = 3x² + 2x - 1

Step-by-step explanation:

got it right on edge

In order to become a member at a gym, there is a $75 startup fee. You then have to pay $15 per month. Write an equation in slope-intercept form modeling this situation where y represents the total cost and x represents the number of months spent at the gym

Answers

Answer:

y = 15x +75

Step-by-step explanation:

15 is the number of months and changes based on how many months

75 doesn't change, remains constant.

Write 0.45 as a fraction.

Answers

Answer:

9/20

Step-by-step explanation:

0.45 = 45/100

45/100=9/20 (divide numerator and denominator by 5)

This is the fraction for 0.45

2. An inaccurate clock loses
3 1/2
minutes every 8 hours. How much time will the clock lose in one
week?

Answers

Answer: 588 min

24x7 x3.5

the sum of 8.23, 7.96 and 17.65​

Answers

Answer:

इएइहेइएबे!!न्बेओएहेजेने

A can of paint will cover 400 square feet. What is the length of the edge of the largest square that can be painted with this can of paint?

Answers

For the area of a circle is πr² as you stated so all you do is set 400 equal to πr² and solve for r.

400=πr²/π
127.32=r²
√127.32)= r
r=11.3

Same thing for this except you use 800 instead of 400 so.

800=πr²
254.64=r²
√254.64)= r
r=15.9 or 16.0 for rounding purposes.

Which of the restricted domains will produce an inverse function for tangent ?
X=-pi, x= pi
X=-pi/2, x=pi/2
X=0, x=pi/2
X=0, x=2pi

Answers

Answer: B) x=-pi/2 , x=pi/2

Step-by-step explanation:

Just did it!

Answer:

B

Step-by-step explanation:

Edge 2020

Marine biologists have been studying the effects of acidification of the oceans on weights of male baluga whales in the Arctic Ocean. One of the studies involves a random sample of 16 baluga whales. The researchers want to create a 95% confidence interval to estimate the true mean weight of male baluga whales. Their data follow a normal distribution. The population standard deviation of weights of male baluga whales is ????=125 kg, and the researchers feel comfortable using this standard deviation for their confidence interval.
Assuming the relevant requirements are met, calculate the margin of error in estimating the true mean weight of male baluga whales in the Artic Ocean.
a. 15.31 kg
b. 51.40 kg
c. 61.25 kg
d. 80.49 kg

Answers

Answer:

c. 61.25 kg

Step-by-step explanation:

The margin of error in estimating the true mean weight of male baluga whales in the Artic Ocean.

a. 15.31 kg

b. 51.40 kg

c. 61.25 kg

d. 80.49 kg

Margin of Error Formula= z × Standard deviation/√n

95% confidence interval = 1.96

Standard deviation = 125kg

n = 16 samples

Margin of error= 1.96 × 125/√16

= 1.96 × 125/4

= 245/4

= 61.25kg

The margin of error in estimating the true mean weight of male baluga whales in the Artic Ocean is 61.25kg

help please!!!!! (QUESTION #3)!!!!!!!

Answers

I’m not sure I’m just guessing but maybe 7x minus 35
Other Questions
you bough shoes for $60. they were on sale for 40% off their original price. a. write a proportion to solve for the original price of the shoes In politics, marketing, etc. we often want to estimate a percentage or proportion p. One calculation in statistical polling is the margin of error - the largest (reasonable) error that the poll could have. For example, a poll result of 72% with a margin of error of 4% indicates that p is most likely to be between 68% and 76% (72% minus 4% to 72% plus 4%).In a (made-up) poll, the proportion of people who like dark chocolate more than milk chocolate was 27% with a margin of error of 1.6%. Describe the conclusion about p using an absolute value inequality.The answer field below uses the symbolic entry option in Mobius. That lets you type in a vertical bar | to represent absolute values. Also, when you type in < and then =, the symbolic entry option will automatically convert that too . In the same way, if you type in > and then =, the symbolic entry option will automatically convert that to .Be sure to use decimal numbers in your answer (such as using 0.40 for 40%). Write the equation of the line in slope intercept form that has the given slope and the y-intercept 4). m=2;y-intercept is -65). m= -1; y-intercept is 36). m= -1/3; y-intercept is -1 A 36.3 kg cart has a velocity of 3 m/s. How much kinetic energy does the object have? Which kind of storage has a spinning platter?magnetic hard diskO serverO solid state hard diskO cloud i need help :( jejeendhndhednndndndn Gary had a 40% discount for new tires. The sale price of a tire was $96.25. What was the original price of the tire? Round to the nearest cent Lucy has $8.15.She loses $3.00.About how much does she have now I NEED THIS ASAP!!Which formula defines the unit for electrical power? please helpcompare. Write , or =. Which is NOT the graph of a function?:te What is the factored form of 250x3 16? Help me pls letter c po A typical elevator car with people has a mass of 1500.0 kg. Elevators are currently approaching speeds of 20.0 m/s - faster than the speed. Required:What is the upward force required if the elevator moves upward 200.0 meters before reaching 20.0 m/s? What is the mass of an object that is accelerated 4 m/s2 by a force of 180 N?kgAsap!!!!!!! My school is giving me a 1-day break for Thanksgiving and I'm very sad, I wanted at least 2-3 days. How did D.W. Griffith's 1915 movie Birth of a Nation impact the status of African-American civil rights?Answers:A) Negatively, because it glorified the Ku Klux KlanB) Negatively, because they blamed the murder of Lincoln on an African-AmericanC) It provided solutions for improved race relationsD) It portrayed African Americans in a positive way I need help, algebra is hard In section 4 of "Justice, Care, and Gender-Bias, Calhoun argues that moral theorists have caused two particular worries by being overly concerned with perfect impartiality. In your own words, explain one of them. if you had two = five what would five + seven be