Element X decays radioactively with a half life of 9 minutes. If there are 610grams of
Element X, how long, to the nearest tenth of a minute, would it take the element to
decay to 124 grams?
y = a(.5) t/h

Answers

Answer 1

A half-life of 9 minutes corresponds to a decay factor k such that

[tex]\dfrac12=e^{9k}\implies k=-\dfrac19\ln\left(\dfrac12\right)[/tex]

Then the time it takes for the substance to decay from 610 g to 124 g is time t such that

[tex]124\,\mathrm g=(610\,\mathrm g)e^{kt}[/tex]

Solve for t :

[tex]\dfrac{62}{305}=e^{kt}[/tex]

[tex]\ln\left(\dfrac{62}{305}\right)=kt[/tex]

[tex]t=\dfrac1k\ln\left(\dfrac{62}{305}\right)\approx20.686[/tex]

so it takes about 20.7 min for the 610 g sample to decay down to 124 g.


Related Questions

I WILL GIVE BRAINLIEST PLEASE HELP

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Answer:

15/19

Step-by-step explanation:

60/4 = 15

76/4 = 19

15/19

Answer:

76/60 i think

Step-by-step explanation:

Mason Crosby kicked a career long 61 yard field goal. How many feet did the ball travel?

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Answer:

fgqwefgwdgnbn8jhvdsihijhofwebhiwg7dyhdg h hy7rhbfwe  r2eery

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A long year-end status report for work is 81 pages long. You need to print 12 copies for a meeting next week. How much is the paper going to cost for those reports? Paper is sold in reams (500 pages) for $3.96 each.

Give your answer to the nearest cent, only for the paper you use (partial reams are OK)

Answers

Answer:

770cents

Step-by-step explanation:

If a report is 81 pages long, 12 copies will be (81 * 12)pages long

12copies = 972 pages long

If 500 pages costs $3.96 each

972 pages will cost $x

Cross multiply

500x = 972 * 3.96

500x = 3,849.12

x = 3,849.12/500

x = 7.69824

Hence the cost of the reports is $7.69824

Convert to cents;

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$7.69824 = y

y = 7.69824 * 100

y = 769.824 cents

y ≈ 770 cents (to the nearest cent.)

Hence the paper is going to cost 770cents (to the nearest cent)

What does 2.89x0.79x1.35= equal?

Answers

Answer: 3.082185x^2

Step-by-step explanation: Find the exact value using trigonometric identities

A patio 44, feet wide is being constructed next to a house. To drain water off the patio and away from the house, a slope of 1/2 inch per foot is necessary. What total

difference in height is required from one edge of the patio to the other?

Answers

Answer:

the total difference in height will be 22 inches

Step-by-step explanation:

since the slope is 0.5 inch per foot, and the patio is 44 feet wide, the end of the patio will be 0.5 x 44 = 22 inches lower

the slope measures how much the height (Y axis) will change as the length (X axis) increases by 1 unit. In this case, since the height decreases as the length increases the slope is negative.  

What is the solution for y=2x+3, y=2x-3

Answers

Answer:.

Step-by-step explanation:

Joe scored 88% on a test. He answered 22 questions correctly. How many questions were on the test

Answers

If Joe got an 88% on a test, answering 22 questions correctly, then there were 25 questions on the test. Divide 22 by 88 and multiply by 100 to find this answer. Please vote my answer as brainliest. I hope this helps

Complete the table by finding the balance A when P dollars is invested at rate r for t years and compounded n times per year. (Round your answers to the nearest cent.)
P = $2500, r = 3%, t = 10 years
n A
1 $
2 $
4 $
12 $
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Answer:

I had this exact question on my test yesterday! That's so crazy!

Step-by-step explanation:

If the measures of Angle 3 is 46 degrees , how much is the measure of angle 6?

Answers

Answer:

Angle 6 = 46°

Step-by-step explanation:

They are alternate interior angles which mean they are congruent

In a semiconductor company's quality control test, a machine found that 14 out of a sample of 234 computer chips were defective. How many of the 4705 such chips that the company makes each month would you expect to be defective?

Answers

Answer:

281-282

Step-by-step explanation:

The cash price of a laptop is $1299. It can be bought at hire purchase by making a deposit of $350 and 10 monthly payments at $120 each.

(i) What is the TOTAL hire purchase

(ii) How much is saved by buying the laptop for cash​

Answers

(i) t = 350 + 120(10) = $1,550
(ii) 1550 - 1299 = save $251

I) The TOTAL hire purchase of the laptop is; $1550

II) The amount saved by buying the laptop for cash is; $251

I) We are told that the laptop can be bought at hire purchase by making a deposit of $350 and 10 monthly payments at $120 each.

Thus;

Cost of laptop by hire purchase = 350 + 120(10)

>> 350 + 1200

>> $1550

II) Since the cash price is $1299, then amount saved = 1550 - 1299

>> $251

Read more about cash price at; https://brainly.com/question/17499675

prove that 1/log (xy)² +1/log(xy²) + log(xy³) =1 there base are x,y and z respectively.​

Answers

Answer:

[tex]1/log (xy)² +1/log(xy²) + log(xy³) =1[/tex]

Step-by-step explanation:

This is your equation, right? Just checking

HOW DO U SIIMPLIFY FRACTIONS!!!!!!!! IM NOT ON A TEST BUT I NEED TO KNOW I WAS ABSENT!!!!!!!!!!!!!!!!!!!!!PLZZZZZZZZZZZZZZZZZZZZZ HELP ASAP

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Answer:

Following are the steps to simplify mixed fractions: Find the highest common factor (HCF) of numerator and denominator of the fraction part. Divide both the numerator and the denominator by HCF. The whole number part will remain the same.

Step-by-step explanation:

Calculate the equation of the line through the points (-1, 1), (4,0), and (24,-4).

Answers

Answer:

slope intercept form: y=-1/5x + 4/5

Approximate the logarithm using the properties of logarithms, given
logb 2 ≈ 0.3562,

logb 3 ≈ 0.5646,
and
logb 5 ≈ 0.8271.
(Round your answer to four decimal places.)
㏒b(2b^3)

Answers

que representa Laos hombres con relacion al total

-5/4c - 1/2 = -3/4 + 5/8c​

Answers

Answer:

c=2/15 have a great day! :D

Step-by-step explanation:

Step 1: Simplify both sides of the equation.

Step 2: Subtract 5/8c from both sides.

Step 3: Add 1/2 to both sides.

Step 4: Multiply both sides by 8/(-15).

3. You receive an order for 0.5 g of Tigan IM. You have a 5 mL vial labeled 100 mg/mL. What is the
volume you will need to fill the order?
a. 2 mL
c. 0.5 mL
b. 5 mL
d. 0.02 mL

Answers

Answer:

52

Step-by-step explanation:

Shelley has a 1 1/2 pound supply of Cat Treats. Each day she gives her kitten 1/8 pound of the treats. How many days will the supply of treats last

Answers

Answer:

The treats will last 12 days.

A swimming pool has two pipes coming into it to fill it with water. One pipe takes 16 hours to fill it. The other takes 12 hours to fill it. How many hours will it take both pipes to fill the pool?

Answers

Answer:

8 hours

Step-by-step explanation:

8 hours because half of 16 is 8 and half of 12 is 6

If it takes 6 hours to fill one half then the other 2 hours would go to the other pipe making it 8 hours

How many squares are in the 20th case​

Answers

Answer:

400

Step-by-step explanation:

1) Fairview and Abbots Rise are 5 in apart on a map that has a scale of 1 in : 18 mi. How far apart are the real cities? 2) A particular satellite is 12 ft wide. A model of it was built with a scale of 1 in :3 ft. How wide is the model? Please help me I have 4 more questoins

Answers

Answer:

1) 90 mi

2) 4 inch

Step-by-step explanation:

1)

Given that the distance between Fairview and Abbots Rise on the map = 5 in

Scale of the map = 1 in: 18 mi

i.e. 1 inch on map is equivalent to an actual distance equal to 18 mi between the cities.

Given that the map has a distance of 5 inches.

Therefore, the actual distance between the cities = 5 [tex]\times[/tex] 18 = 90 mi

2) A particular satellite is 12 ft wide.

Model's scale = 1 in : 3 ft

i.e. 1 inch on map is equivalent to actual distance of 3 ft.

OR

3 ft of actual distance = 1 in on map

1 ft of actual distance = [tex]\frac{1}{3}[/tex] in on map

12 ft of actual distance = [tex]\frac{1}{3}\times 12 = \bold{4\ inch}[/tex]

8. King has started jumping rope as part of his exercise routine. He keeps track of his jumps and time spent jumping to map his progress. Most recently, he jumped 497 times in 7 minutes. Which of the following describes king's pace?​

Answers

Answer:

cockdabackdecockdacoin

Step-by-step explanation:

huuuuuuuuuuuuuuuuuuuuu

Answer:

71 times per minute

Step-by-step explanation:     497/7=71

A bicycle is traveling at 21 miles per hour. How many feet will it cover in 35 second?

Answers

The answer is an estimate of about 943.36 feet.

A rectangular prism has a volume of 686 cubic units. How many unit cubes would fill the volume of the solid if they were packed without any gaps or overlaps?

Answers

Answer:

2 unit cubes of 7 units side length can fill the volume of the solid without overlap

Step-by-step explanation:

Volume of a cube is L^3

Let the number of cubes be n

Since the cubes are similar,

then;

nL^3 = 686

nL^3 = 343 * 2

By inspection

L^3 = 343 (since it is a perfect cube and the cube root is 7)

n = 2

(5 marks)
b) Anthony plans to take up business and purchase a shop lot near his home. He saves
RM10,000 in an account that pays 6% compounded every four months. Four years
later, he withdrew all his money to pay for the down payment of the shop lot.
D)
Find the value of the down payment.
(3 marks)​

Answers

I thought this right but sorry if it is wrong

first make the 6% in amount by 6×10,000÷100=3600

then, the convert 4 year into month by (4×12)=48month. after that divide 48months by 4 month.i.e.48÷4=12.at last multiply 12 by 3600.i.e. 12×3600=43200

the weights of steers in a herd are distributed normally. the standard deviation is 200lbs and the mean steer weight is 1400lbs. find the probability that the weight of a randomly selected steer is less than 1859lbs

Answers

Answer:

The probability that the weight of a randomly selected steer is less than 1859lbs is 0.9890

Step-by-step explanation:

Given

Mean = 1400 lbs

SD = 200 lbs

In order to find the probability of a random variable x we have to find the z-score of the data point.

z-score is calculated by:

[tex]z = \frac{x-mean}{SD}[/tex]

Putting x=1859

[tex]z = \frac{1859-1400}{200}\\z = \frac{459}{200}\\z = 2.295[/tex]

The z-score for 1859 is 2.295

We have to use the z-score table to find the required probability

So,

[tex]P(z<2.295)\ or\ P(x<1859) = 0.9890[/tex]

Hence,

The probability that the weight of a randomly selected steer is less than 1859lbs is 0.9890

A researcher developing scanners to search for hidden weapons at airports has failed to conclude that a new scanner is significantly better than the current scanner. He made his decision based on a test using α=0.025.

a. Would he have made the same decision at α=0.20?
b. How about α=0.005? Explain.

Answers

Answer:

a. not sure

b. yes

Step-by-step explanation:

According to the given scenario, the following information is mentioned

[tex]\alpha[/tex] =0.025

In the case when the alpha is equivalent to 0.025 so the p test value would be more than the significance level i.e. 0.025 as the prescribed test is not important

So here

p>0.025

In the above case i.e. p>0.025 this does not mean that p>0.2 so we are not sure about this case whether he made teh same decision or not

Now in the another case, if the significant level is 0.005 so we are sure that p>0.005 as it is more than 0.025 so here also the test is not significant

So, here the same decision could be made

-12x4m8n 6x5m-10n-6​

Answers

Answer:

whats the qeustion

Step-by-step explanation:

What’s the question ?

True or false
If a prime number is greater than 2, it is odd

Answers

Answer:

true

Step-by-step explanation:

if a prime number were even, and greater than 2, they would be able to be divisible by 2 and therefore not a prime number

Answer:true

Step-by-step explanation:

A prime number is a number that can only be multiplied by 1 to get itself, an even number is a number that can be multiplied by 2. Thus it is true.

HELPPPP PLZ
Savannah drew a map of Texas for her Geography class. According to Savannah’s map scale, one-half inch on the map represents approximately 77.5 kilometers. If the actual distance from Austin to El Paso is approximately 930 kilometers, what is the approximate distance between Austin and El Paso on Savannah’s map?
A.24 inches
B.2 inches
C.6 inches
D.12 inches

Answers

Answer:

A

Step-by-step explanation:

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