Element X is a radioactive isotope such that every 69 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 20 grams, how much of the element would remain after 30 years, to the nearest whole number?

Answers

Answer 1

Answer:

[tex]15\text{ grams}[/tex]

Step-by-step explanation:

Since the mass of the radioactive isotope is halved every 69 years, we want to multiply its initial mass by [tex]1/2[/tex] every 69 years.

We can model this using the following equation:

The remaining mass, [tex]f(x)[/tex], is equal to the initial mass multiplied by [tex]\frac{1}{2}^{(\frac{t}{69})}[/tex], where [tex]t[/tex] is the number of years that have passed from the initial mass. The reason why the exponent is [tex]\frac{t}{69}[/tex] is because we only want to half the mass every 69 years, so [tex]\frac{69}{69}=1[/tex] and [tex]\frac{1}{2}^1=\frac{1}{2}[/tex].

Thus, we have:

[tex]f(x)=20\cdot \frac{1}{2}^{(t/69)}[/tex]

Substituting [tex]t=30[/tex], we get:

[tex]f(x)=20\cdot \frac{1}{2}^{(30/69)}=20\cdot 0.73980522316=14.7961044632\approx \boxed{15\text{ grams}}[/tex]


Related Questions

The voltage E in an electrical circuit is modeled by E=3.8cos(110π t). What is the maximum voltage?

Answers

Answer:

Max E=3.8 Voltage

Step-by-step explanation:

[tex]maximum-value -of cos(\theta) =1, when \theta=0,360,720\\110\pi t=0, therefore t=0, 1.04, 2.08 etc[/tex]

The maximum voltage for the electric circuit is E = 3.8 when the value of the trigonometric function cos(110π t) has the maximum value = 1, from the range of cosine function.

What is the range of the trigonometric function cosine?

The range of the trigonometric function of cosine, that is, cos θ, is [-1, 1], that is, -1 ≤ cos θ ≤ 1.

How do we solve the given question?

We are given that the voltage E in an electrical circuit is modeled by E = 3.8cos(110π t).

We are asked to find the maximum voltage E that can be obtained from the circuit.

The voltage E = 3.8cos(110π t).

In the given formula 3.8 is constant and cos(110π t) is variable. The value of E is maximum when the trigonometric function cos(110π t) attains the maximum value.

Since its a cos function, the maximum value it can attain = 1, as the range of the trigonometric function of cosine, that is, cos θ, is [-1, 1], that is, -1 ≤ cos θ ≤ 1.

When the variable attains the maximum value = 1, the value of the voltage E  = 3.8*1 = 3.8.

∴ The maximum voltage for the electric circuit is E = 3.8 when the value of the trigonometric function cos(110π t) has the maximum value = 1, from the range of cosine function.

Learn more about the ranges of trigonometric functions at

https://brainly.com/question/9565966

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You are on a ship at sea. You see a lighthouse in the distance. You know the lighthouse is 145 feet tall. You measure the angle of elevation to the top of the lighthouse at 5 degrees. How far are you from the bottom of the lighthouse? *

Answers

Answer:

1657.14 ft

Step-by-step explanation:

Tan = opposite / adjacent

tan 5 = 145 / adjacent

0.0875 =  145 / adjacent

adjacent = 145 / 0.0875

= 1657.14 ft


For the function Rx) = 1/x+1 which of these could be a value of F(x) when x is
close to -1
O A. -0.01
OB. 0.01
O c. 1
O D. -10,000

Answers

Answer:

D. -10000

Step-by-step explanation:

you really need to copy or type the question better.

I can only assume what you really mean.

I guess, you want to say that F(x) = 1/(x+1)

when the value for x gets close to -1, the whole expression gets close to 1/0, which would bring numbers with larger and larger absolute values, leading to infinity.

you also did not say from what direction we are getting closer to -1.

we could come from -2 and move closer and closer to -1.

in this case (x+1) would always be smaller than 0 (negative sign).

or we could come from +1 and then 0 and move towards -1, in which case (x+1) would airways be bigger than 0 (positive sign).

anyway, when being closer and closer to -1, the absolute value of the resulting functional values will get bigger and bigger.

the only answer option with a larger absolute value is D (-10000).

so, that had to be the solution, and it also means that we are coming from -2 to -1, and the sign is negative.

Math help please due today ill give you brainlist if correct !!!

Answers

Answer:

a. Vertical

b. Corresponding

c. Alternate exterior

d. Supplementary

e. 40 degrees

f. 40 degrees

Table

45  45  135

20  70  160

87   3    93

Step-by-step explanation:

a. Vertical angles are congruent and opposite each other.

b. Corresponding angles are congruent and are located in similar positions.

c. Alternate exterior angles are congruent and opposite each other when a line intersects two parallel lines.

d. Supplementary angles are next to each other and add to 180 degrees.

e. Supplementary angles. Subtract 140 from 180 to find <M.

f. Alternate interior angles. <X and <M are congruent.

Table

Complementary angles add to 90 degrees. Supplementary angles add to 180 degrees.

45 + 45 = 90

45 + 135 = 180

etc.

If you put 700 into a savings account that's earns 1% interest compound monthly how much will you have in 5 years

Answers

Answer:

In 5 years I will have $ 1,151.71.

Step-by-step explanation:

To determine, if I put 700 into a savings account that's earns 1% interest compound monthly, how much will I have in 5 years, the following calculation must be performed:

700 x (1 + 0.01 / 12) ^ 12x5 = X

700 x (1 + 0.008333) ^ 60 = X

700 x 1.64530 = X

1,151.71 = X

Therefore, in 5 years I will have $ 1,151.71.

The measures of the angles of a triangle are shown in the figure below. Solve for x.

Answers

Answer:

x=57°

Step-by-step explanation:

the sum of the measures of the angles of a triangle add up to 180°.

it is given that there is a 33°, and a right angle which is 90°.

to find x:

x=180°-(90°+33°)

x=180°-123°

x=57°

Answer:

180° - 33° - 90° = 57°

x = 57°

If b=3-2s and A= -2s^2+2s+3 find an expression that equals 2b+2A in standard form

Answers

2(3-2s)+2(-2s^2+2s+3)

I think this might be the answer you’re looking for so best of wishes and good luck!!

There is a bag with only red marbles and blue marbles. The probability of randomly choosing a red marble is 1 /9 . There are 63 marbles in total in the bag and each is equally likely to be chosen. Work out how many red marbles there must be.

Answers

Answer: 7 red marbles.

Step-by-step explanation:

Since we are given the information that there are only red marbles and blue marbles in the bag and that the probability of randomly choosing a red marble is 1 /9 while there are 63 marbles in total.

Then the number of red marbles will be:

= 1/9 × 63

= 7

There are 7 red marbles

The number if blue marbles will be:

= 63 - 7

= 56 blue marbles

has endpoints J(13, 8) and K(–6, –6). Find the coordinates of the midpoint of .

Answers

Answer:

the midpoint of it is 8,-6

Step-by-step explanation:

rhgsr egh

Please help I’ll give brainliest

Answers

Answer:

The rules for standard form are

Small numbers can also be written in standard form. However, instead of the index being positive (in the above example, the index was 3), it will be negative. The rules when writing a number in standard form is that first you write down a number between 1 and 10, then you write × 10(to the power of a number)

I hope this helps

Answer:

False

Step-by-step explanation:

Please Mark me brainliest

The weight of three articles is 856 kg. If two of the articles weigh 502kg, what is 1/2 the weight of the third article?

Answers

Answer:

177 kg

Step-by-step explanation:

Find the weight of the third article by finding the difference between 502 and 856, since 856 kg is the total weight and 502 kg is the weight of the other 2 articles:

856 - 502

= 354

Now, find 1/2 of the weight, by dividing this by 2:

354/2

= 177

So, 1/2 the weight of the third article is 177 kg

Make 'r' the subject of this formula: 3r - 5 = p

Answers

Answer:

hey I am not about what the question says but I think this is the answer:

3r=p+5

so the subject is 3r

3r - 5 = p
3r = p + 5
r = p + 5/3

Point P (a, b), where neither a orbis equal to 0, is subject to the following operations, one after the other in any order:
reflection about the x-axis, reflection about the y-axis, reflection about the origin.
What will be the final position of point P?

Answers

Answer:

(a, b)

Step-by-step explanation:

Transformation is the movement of a point from its initial location to a new location. Types of transformation are rotation, reflection, dilation and translation.

Reflection is the flipping of an object about a point. If a point A(x, y) is reflected over x axis, the new point is at A'(x, -y). If the a point A(x, y) is reflected over y axis, the new point is at A'(-x, y). If a point A(x, y) is reflected over origin, the new point is at A'(-x, -y).

Given point P(a, b). It reflection about the x-axis gives P'(a, -b), then the reflection about the y-axis gives P"(-a, -b). Lastly, reflection about the origin gives P"'(a, b)

How many eighths does it take to equal 1/4 model

Answers

Answer:

2 eighths.

Step-by-step explanation:

Answer:

2 eighths

Step-by-step explanation:

1/8 + 1/8 = 2/8 or 1/4

Solve the absolute value inequalty ⎜3x + 5⎟≤ - 2 a No Solution b - 2 ≤ x ≤ - 7 c All real numbers d -7/3 ≤ x ≤ -3/7

Answers

Answer:

Step-by-step explanation:

First, absolute value is always POSITIVE ⇒ the given inequality has No Solution!!

Just to show you how to solve this kind of problems:

1). If (3x + 5) ≥ 0, then 3x + 5 ≤ - 2

3x ≤ - 5 - 2

3x ≤ - 7

x ≤ - [tex]\frac{7}{3}[/tex]

2). If (3x + 5) < 0, then - (3x + 5) ≤ - 2

3x + 5 ≥ 2

3x ≥ - 3

x ≥ - 1

x ∈ ∅

Find mZSGH if mZFGH = 108°

Answers

Answer:

22

Step-by-step explanation:

FGH - FGS = SGH

108 - 86 = 22

Answer:

∠ SGH = 22°

Step-by-step explanation:

∠ FGS + ∠ SGH = ∠ FGH , that is

86° + ∠ SGH = 108° ( subtract 86° from both sides )

∠ SGH = 22°

can someone help me I don't understand ​

Answers

Answer:

(a) 165 m/min

(b) 107.14m/min

Step-by-step explanation:

The slope of the distance time graph gives speed.

Here, the speed of the segment A is

[tex]v_A= \frac{900-0}{4-0}=225 m/min[/tex]

The speed of segment B is

[tex]v_B= \frac{1500- 900}{14-4}= 60 m/min[/tex]

(a) The change in speed is

= 225 - 60 = 165 m/min

(b) The average speed is defined as the ratio of total distance to the total time.

So, the average speed is

[tex]= \frac{1500}{14}= 107.14 m/min[/tex]

someone plz help me!!

Answers

Answer:

P'=(0,3)

Step-by-step explanation:

P'=(-5+5, 7-4)

Find y.
Round to the nearest tenth:
31°
у
х
400 ft
y = [ ? ]ft

Answers

y equals 240.3 ft. This is because the bottom angle of the triangle is an alternate interior angle to 31 degrees, so it is also 31 degrees. You can then create the equation tan31=y/400. To find y multiply each side by 400 and you’ll get 240.344

The quartile deviation and coefficient of quartile deviation of a continuous frequency distribution are 2 and 0.25 respectively. Find lower and upper quartiles.

Answers

Answer:

Lower quartile = 6

Uppwr quartile = 10

Step-by-step explanation:

Coefficient of quartile deviation = 0.25

Quartile deviation = 2

Coefficient of quartile deviation = (Q3 - Q1) / (Q3 + Q1)

Quartile deviation = (Q3 - Q1) / 2

Hence;

Quartile deviation = (Q3 - Q1) / 2 = 2

Q3 - Q1 = 2 * 2

Q3 - Q1 = 4 - - - - (1)

Q3 = 4 + Q1 - - - - (2)

(Q3 - Q1) / (Q3 + Q1) = 0.25

Q3 - Q1 = 4

4 = 0.25(Q3 + Q1)

Q3 + Q1 = 4 / 0.25

Q3 + Q1 = 16 - - - - (3)

Put Q3 = 4 + Q1 in (3)

4 + Q1 + Q1 = 16

4 + 2Q1 = 16

2Q1 = 16 - 4

Q1 = 12 / 2

Q1 = 6

Q3 = 4 + Q1

Q3 = 4 + 6

Q3 = 10

A bicycle has a cash price of $319.95. It can be bought on hire purchase with a deposit of $69 and ten monthly installments of $28.50 each.​

a. what is the total hire purchase price of the bicycle?

b. Find the difference between the hire purchase price and the cost price of the bicycle.

Answers

Answer:

a. $354

b.$34.05p

Step-by-step explanation:

10 monthly instalments

10x28.5=280

plus the deposit 280+69=354

The difference between 354 and 319.95 is 34.05  

a. The total hire purchase price of the bicycle is $354.

b. The difference between the hire purchase price and the cost price of the bicycle is $34.05.

a. Total hire purchase price:

Total hire purchase price=(10 months×$28.5)+$69

Total hire purchase price=$285+$69

Total hire purchase price=$354

b. Hire purchase price and cost price:

Difference=$354-$319.95

Difference=$34.05  

Inconclusion the total hire purchase price of the bicycle is $354 and the difference between the hire purchase price and the cost price of the bicycle is $34.05.

Learn more about  hire purchase price here:https://brainly.com/question/24730392

Direction: Fill the missing terms. Write your answer on the space provided.1. .An _______ is a data collection method where you as a researcher change somevariables and observe their effect on other variables.2. A __________ is a data collection method where you select a sample of respondentsfrom a large population in order to gather information about that population.3. __________, when you use this method, you meet with the respondents face to faceand ask questions.4. In an __________ method, the data from the field is gathered with the help ofobservation by the observer.5. ___________ is sent ( by post or by mail) to the persons concerned with a requestto answer the questions and return the questionnaire.6. ___________.It is a process by which the researcher collects/gathers theinformation needed to answer the research problem.7. __________ It is very similar to the questionnaire method. The main differenceis that the schedule is filed by the enumerator who is specifically appointed for thepurpose.8. __________ One who goes to the respondents, asks them the questions from thequestionnaire in the order listed, and records the responses in the space provided.9. __________are those which have already been gathered by someone else andwhich have through some statistical analysis.10. . ___________ are those which are gathered for the first time and are original incharacter.

Answers

Answer:

An experiment is a data collection method where you as a researcher change somevariables and observe their effect on other variables.A surveys is a data collection method where you select a sample of respondentsfrom a large population in order to gather information about that population.☞☜ ☞☜ ☞☜ Data collection It is a process by which the researcher collects/gathers theinformation needed to answer the research problem.☞☜ ☞☜ Secondary data are those which have already been gathered by someone else andwhich have through some statistical analysis.Primary data are those which are gathered for the first time and are original incharacter.

Step-by-step explanation:

lm.ao I don't know 3,4,5,7,8 I'm sincerely apologise for this!!

•|۝ jess bregoli ۝|•

#keep learning!!

Answer:

Here is your Answer : )

Step-by-step explanation:

1. experiment

2. survey

3.  Interview

4. observation

5. questionnaire

6. Data collection

7. Schedule

8. Manager

9. primary data

10. Primary data

Plz mark as brainiest this took long time

Hope U like it : )

A purse regularly priced at $70 is on sale for 20% off. What is the scale price of the purse?

Answers

The answer should be $56


Simplify (12^0)(12^6). Write your answer using an exponent. Explain how you found your answer.​

Answers

Step-by-step explanation:

(12^0)(12^6)

1 ×12⁶. (a⁰=1, a is a number)

=12⁶

i need the base and hight

Answers

Answer:

Height = 5 and Base = 10

Step-by-step explanation:

The base of the parallelogram is twice the perpendicular height of the parallelogram. The area of the parallelogram is 50 cm².

Formula for area of parallelogram = base × height

Base = 2h

Height = h

∴ Area = 2h × h = 50

Solution:

2h × h = 50

2h² = 50

[tex]\frac{2h^{2} }{2} = \frac{50}{2}[/tex]

h² = 25

[tex]\sqrt{h^{2} } = \sqrt{25}[/tex]

h = 5

∴ height = 5 and base = 2(5) = 10

Craig threw a handful of identically shaped buttons into the air then collected 14 bottoms that landed on the carpet. Is this sample of the buttons likely to be biased yes or no

Answers

Answer:

possible?? but I think that there is a typo, and that there would not be a bias

Step-by-step explanation:

can we assume that there are no typos in the question

he threw BUTTONS in the air, and look at buttons that landed with the BOTTOMS facing up ??? in that case the weight might bias the orientation of the landing... I think that you have a typo and it just says that he collected 14 BUTTONS, in that case given that they are "IDENTICAL" we most likely can assume that there would be no bias (size color, texture are all the same)

Elena is trying to figure out how many movies she can download to her hard drive. The hard drive is supposed to hold 500 gigabytes of data, but 58 gigabytes are already taken up by other files. Each movie is 8 gigabytes. Elena wrote the inequality 8x + 58 ≥ 500 and solved it to find the solution x ≥ 55.25.

1.Explain how you know Elena made a mistake based on her solution.

2.Fix Elena’s inequality and explain what each part of the inequality means.

Answers

Answer:

x is 69.75

Step-by-step explanation:

8x+58>500

500-58

8x/8>558/8

x>

What is the slope and y intercept of the equation?
y=1/2x
m=
b=

Answers

⊹˚ʚ ❑Answer︰slope is 1/2 and y-int. is 0

      ✎Daily reminder: make sure to eat food and stay hydrated, have a good day :D

Solve 2 ≤ 2x + 4 < 10 for x.

–1 ≤ x < 3
1 < x < 3
–1 < x < 3
1 ≤ x < 3

Answers

Answer:

-1 ≤ x  < 3

Step-by-step explanation:

2 ≤ 2x + 4 < 10

Subtract 4 from all sides

2-4 ≤ 2x + 4-4 < 10-4

-2 ≤ 2x  < 6

Divide all sides by 2

-2/2 ≤ 2x/2  < 6/2

-1 ≤ x  < 3

Which of the following is a quadratic function?

Answers

Answer:

A

Step-by-step explanation:

A

when multiplied out

the highest exponent of x is 2

y = 2x² + x - 6

Answer:

option A

Step-by-step explanation:

A quadratic equation is a single variable polynomial of degree 2.

[tex]A ) y = ( x + 2)(2x-3) = 2x^2 -3x +4x - 6 =2x^2 + x - 6 \ - Yes \\\\B) y = 3(x - 4) \ - No\\\\C) y = \frac{1}{x^2} \ - No\\\\D) y = x(x-4)(x+3) = x(x^2 -x - 12) = x^3 -x^2 - 12x \ - No[/tex]

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A review of combination What best describes life for young women working in factories in the United States in the early 1800s?O safe conditions, long hours, and a chance to get richO healjky risks, short work days, and a sense of freedomO unsafe conditions, health risks, and a new sense of freedomo unsafe conditions, chances for education, and eight-hour work days Answer the following questions1. Heat in liquid travels froma) bottom to topb) top to bottomc) left to rightd) right to left2. The direction of flow of heat is a) always from a cooler body to a hotter bodyb) always from a hotter body to cooler bodyc) always from a body at a lower temperature to a body at a higher temperature d) all the above3. A cold steel spoon is dipped in a cup of hot milk. The steel spoon transfer the heat to its other end by the process of a) convectionb) conductionc) radiationd) none of the above