The half-life of radon-222 (Rn-222) is 3.823 days.How long would it take for three half-lives?

Answers

Answer 1

Answer: [tex]7.949\ \text{days}[/tex]

Step-by-step explanation:

Given

The half-life of a sample is [tex]T_{\frac{1}{2}}=3.823\ \text{days}[/tex]

Decay is given by

[tex]A=A_o2^{\dfrac{-t}{T_{\frac{1}{2}}}}[/tex]

After 3 half-lives, one-eight of the sample is left

Insert the values

[tex]\Rightarrow \dfrac{A_o}{8}=A_oe^{\dfrac{-t}{T_{\frac{1}{2}}}}\\\\\Rightarrow e^{\dfrac{t}{T_{\frac{1}{2}}}}=8\\\\\text{Taking log both sides}\\\Rightarrow \dfrac{t}{T_{\frac{1}{2}}}=\ln 8\\\\\Rightarrow t=3.823\times \ln 8\\\\\Rightarrow t=7.944\ \text{days}[/tex]

Answer 2

Answer:

What is this… mortal kombat

Step-by-step explanation:


Related Questions

Tell whether the equation has one, zero, or infinitely many solutions.

4(x − 8) + 9 = 4x − 23

Answers

Answer:

Infinitely many solutions.

Step-by-step explanation:

4(x-8)+9=4x-23

4x-32+9=4x-23

4x-23=4x-23

infinitely many solutions.

help me please and hurry up please anyone

Answers

Answer:

I think its D

In Mr Bunnelo's class, 19 out of 26 students wore their school shirt on Friday. If the school has a
population of 2,462 students, approximately how many students at the school wore their school shirt
on Friday?


95 students
130 students
O
663 students
1,799 students

Answers

the answer is 1799 students

id appreciate some help ^^

Answers

Answer:

392

Step-by-step explanation:

I would separate this into 2 shapes a triangle and a square. So first take the area of the square

area of square = base x height

16x19=304

Than take the area of the triangle

area of triangle = 1/2(base x height)

you can find the height of the triangle by subtracting 19 from 30 which is 11, and the base is the same as the base of the square which is 16

1/2(16x11)= 88

Add them together

304+88=392

Answer: 392 in^2

Step by step solution: See photo

If a fair coin is tossed 4 times, what is the probability, to the nearest thousandth, of getting exactly 3 tails?

Answers

Answer:

000.3

Step-by-step explanation:

The probability of getting exactly 3 tails is 0.25 If a fair coin is tossed 4 times, what is the probability.

What is probability?

It is defined as the ratio of the number of favorable outcomes to the total number of outcomes in other words the probability is the number that shows the happening of the event.

We have a coin if it is tossed 4 times.

Then the probability of getting exactly 3 tails is:

[tex]=\rm 4 C_3(\frac{1}{2} )^3\times (1-\frac{1}{2} )^1[/tex]

[tex]=\rm 4\times \frac{1}{16}[/tex]

= 1/4

= 0.25

Thus, the probability of getting exactly 3 tails is 0.25 If a fair coin is tossed 4 times, what is the probability.

Learn more about the probability here:

brainly.com/question/11234923

#SPJ2

The diameter of a pipe is 6 cm. If the pipe is 26 cm long, what is its volume?
Use the value 3.14 for π , and round your answer to the nearest whole number.
Be sure to include the correct unit in your answer.

Answers

i think this question answer is 734.76cm^3

HAVE A NICE DAY
WILL GIVE BRAINLST :)

Answers

Answer:

Corresponding angles...

1 and 5

2 and 6

3 and 7

4 and 8

Alternate Interior Angles

3 and 6

4 and 5

Alternate Exterior angles

1 and 8

2 and 7

A washer and dryer cost $1000 combined. The of the washer is three times the cost of the dryer. What is the cost of the dryer?

Answers

Let “x” represent the cost of the dryer in dollars
The washer costs 3x dollars

3x + x = 1000
4x = 1000
x = 250

The dryer is $250

Marie grew 10 plants with 2 seed packets. How many seed packets does Marie need to have a total of 15 plants in her backyard? Solve using unit rates

Answers

Answer:

he need 3 seeds to plant a 15 plant

A. 15
B. 75
C. 100
D. 105

Answers

Answer:

B. 75

Step-by-step explanation:

According to vertical angles theorem, angles that are opposite of one another with shared lines will be equal, so we can set 5x = x +60.

Solving for x, we get x = 15, and substituting into the angle we get 15 + 60 = 75 degrees.

The angle of elevation to the top of the Empire State Building in New York is found to be 11° from the ground at a distance of 5281 feet from the base of the building. Using this information, find the height of the Empire State Building in feet. Use the dimensions given in the diagram to give an equation and solve. Round two decimal places.

Answers

Answer:

The height of the building is of 1026.52 feet.

Step-by-step explanation:

This situation is modeled by a right triangle, in which the length of the opposite side to the angle of 11º is the height of the building, while the length of the adjacent side is of 5281 feet.

Tangent:

In a right triangle, the tangent of an angle is the length of the opposite side divided by the length of the adjacent side.

In this question:

[tex]\tan{(11)} = \frac{x}{5281}[/tex]

[tex]x = 5281*\tan{(11)}[/tex]

Using a calculator, we have that the tangent of 11 degrees is: 0.1944. Thus:

[tex]x = 5281*\tan{(11)} = 5281*0.1944 = 1026.52[/tex]

The height of the building is of 1026.52 feet.

Question 17 (1 point)
Bicycle, a company that makes dice, is looking to change the size of the dice they produce. The current dice have edge lengths of 5mm, and the company wants to increase them to 15mm. How will the volume of the dice be effected if this change is made?

Question 17 options:

30x larger


3x larger


10x larger


27x larger

Answers

Answer:

3x

Step-by-step explanation:

Which polynomial represents the sum below?

Answers

Answer:

D

Step-by-step explanation:

which expression show 50+30 written as a product of two factor​

Answers

Answer:10(5+3)

I Really Hope This Helps<3!

help.......................................
12 + 8 + 2 + 21 + 31 x 12 √ 2

Answers

Answer:

569.

Step-by-step explanation:

Answer:

12+8+2+21+31×12√2

BODMAS

so start with multiplication

12+8+2+21+372√2 = 43+372√2=569.09

The surface area of the world is about 7/10 water. If a very small, non-dangerous meteoroid lands on the earth, what is the probability it does NOT land in the water?

Answers

Answer: 3/10 probability

Step-by-step explanation:

We are telling the probability with tenths, so we can say that the probability of the meteoroid landing on Earth is 3/10.

If the surface area of the world is approximately 7/10, or 70 percent, water, there is approximately 3/10, or 30 percent, chance of the meteoroid hitting land.

I'm pretty sure, at least ^_^

3/10I answered this on my test

I WILL GIVE YOU BRAINLIEST AND THIS ANSWER IS WORTH 30 POINTS!

1. |18-x|, if x<18.
2.|x-5|,if x<5
3. |x-18|, if x<18

Answers

Answer: the answer is  |x-5,if x<5|

Step-by-step explanation:

50 POINTS !!


PLEASE HELP !! ILL GIVE BRAINLIEST TO THE RIGHT ANSWERS.

Answers

Answer:

12

Step-by-step explanation:

Use the pythagorean theorem ([tex]a^2+b^2=c^2[/tex]). A and b are the two legs of the triangle, and c is ALWAYS the hypotenuse. Plug in the values for a and c

[tex]a^2+b^2=c^2[/tex]

[tex]5^2+b^2=13^2[/tex]

[tex]25+b^2=169[/tex]

[tex]b^2=144[/tex]

[tex]b=12[/tex]

Answer:

b = 12m

Step-by-step explanation:

5^2 + b^2 = 13^2

25 + b^2 = 169 --> *subtract 25 form both sides*

b^2 = 144 --> find square root of 144*

b = 12

Can you help me. 12.95 + 0.4 + 0.3 + 0.09 = ?

Answers

Answer:

13.74

Step-by-step explanation:

Answer:

13.74

Step-by-step explanation:

Add 0.4+0.3 = 0.7, so the equation now looks like this: 12.95+0.7+0.09

Add 0.7 + 0.09 = 0.79, so the equation now looks like this: 12.95 + 0.79

Add 12.95 + 0.79, so now you are left with: 13.74

hope this helps, ask me if you need more explanation

PLEASE HELP ME ASAP I AM STRUGGLING SO MUCH MY WORK IS LITERALLY DUE NOW I'VE BEEN UP ALL NIGHT TRYING TO SOLVE IT AND MY ONLY SOLUTION IS TO ASK FOR HELP SO PLEASE HELP ME IF U CAN ​

Answers

As it is a straight line all the angles add up to 180 so 5s+18+48-a+8a-30= 180 so simplified 12a+36=180 then solve to get a=12.17 so then when u put 12.17 as a you get 5 * 12.17 +8 =78.85 then 48-12.17 which is clearly<78.85 then you do the final angle of 8*12.17-30 which is 67.36 so angle AOC is the biggest

(5a + 18) + (48 - a) + (8a - 30) = 180

5a + 18 + 48 - a + 8a - 30 = 180

5a - a + 8a + 18 + 48 - 30 = 180

12a + 36 = 180

12a = 180 - 36

12a = 144

a = 12

Plsss helppp!!!!!!!!!!!!!!

Answers

Answer:

yes

Step-by-step explanation:

A statistical question is one that can be answered by collecting data and where there will be variability in that data.

because not every father would be born on the same day this is a statistical question.

How are these triangles congruent ?
- HL
- AAA
- ASA

Answers

ASA..........................

The circle graph shows how a family budgets its annual income. If the total annual income is $135,000, what amount is budgeted for Food?

Answers

Answer:

$22950 is budgeted for FOOD.

Step-by-step explanation:

=17% of 135000

=0.17*135000

=$22950

Which ordered pair best describes the point plotted in Quadrant II on the coordinate plane shown?


A. (-4, 6 )

B. (6, 4 )

C. (4, -6)

D. (6, -4 )

Answers

Answer:

A. (-4, 6 )

Step-by-step explanation:

Signals of x and y in each quadrant:

Suppose we have a point P(x,y).

In the first quadrant, we have that both are positive, that is, x > 0, y > 0.

In the second quadrant, x is negative, while y is positive, that is, x < 0, y > 0.

In the third quadrant, both are negative, that is, x < 0, y < 0.

In the fourth quadrant, x is positive while y is negative, that is, x > 0, y < 0.

In this question:

In the second quadrant, we have x negative and y positive, so the ordered pair that best describes is given by option A.

Me puedes ayudar es para hoy porfavor ​

Answers

Answer:

mira a las base de las figuras y busca cual base matchs con la figuras de la figura prinsipal

Step-by-step explanation:

como el cono va con la del toda la izquierda de la de la mitad

what is the value of x ?

Answers

Answer:

x = 19

Step-by-step explanation:

The two angles form a right angle

A right angle has a measure of 90 degrees

Thus, x + 14 + 3x = 90

               ^This is the equation we will use to solve for x

x + 14 + 3x = 90

step 1 combine like terms

x + 3x = 4x

we now have 4x + 14 = 90

step 2 subtract 14 from each side

90 - 14 = 76

14 - 14 cancels out

we now have 76 = 4x

step 3 divide each side by 4

4x / 4 = x

76 / 4 = 19

we're left with x = 19

find the value of x in the polygon

Answers

Use the Pythagorean theorem (a^2+b^2+x^2)

x equals to 10.............

PLEASE HELP ALL LINKS GIVEN WILL BE REPORTED

Answers

Answer:

- 13

Step-by-step explanation:

[tex]log \frac{ {a}^{6} {b}^{6} }{ {c}^{7} } \\ \\ = log( {a}^{6} {b}^{6} ) - log {c}^{7} \\ \\ = 6log \: a + 6log \: b - 7log \: c \\ \\ = 6(2) + 6( - 3) - 7(1) \\ \\ = 12 - 18 - 7 \\ \\ \therefore \: log \frac{ {a}^{6} {b}^{6} }{ {c}^{7} } = - 13[/tex]

Yea the answer is -13 I just took the test

Can somebody help me seriously

Answers

Answer: b

Step-by-step explanation:

I don't know but i am right

There are 4 consecutive integers that sum to 394. What is the least of these integers?​

Answers

Answer: 97

Step-by-step explanation:

394 / 4 = 98.5, so the 4 numbers must be around 98.5.

97 + 98 + 99 + 100 = 394

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