A sample of a radioactive substance decayed to 97% of its original amount after a year. (Round your answers to two decimal places.) (a) What is the half-life of the substance

Answers

Answer 1

Answer:

23 years

Step-by-step explanation:

Step 1: Calculate the rate constant (k) for the radioactive decay

A radioactive substance with initial concentration [A]₀ decays to 97% of its initial amount, that is, [A] = 0.97 [A]₀, after t = 1 year. Considering first-order kinetics, we can calculate the rate constant using the following expression.

ln [A]/[A]₀  = - k.t

k = ln [A]/[A]₀ / -t

k = ln 0.97 [A]₀/[A]₀ / -1 year

k = 0.03 year⁻¹

Step 2: Calculate the half-life of the substance

We will use the following expression.

[tex]t_{1/2}[/tex] = ln2/ k = ln 2 / 0.03 year⁻¹ = 23 years


Related Questions

Consider the graph of g(x) = –2x2 + 8x – 10. Identify the y-intercept, the vertex, and the zeros of the function.
Question 10 options:

A)

y-intercept: (0, 10); vertex: (–2, 2); zeros: none

B)

y-intercept: (0, –10); vertex: (2, –2); zeros: (0,0) and (4,0)

C)

y-intercept: (0, –10); vertex: (2, –2); zeros: (0,0)

D)

y-intercept: (0, –10); vertex: (2, –2); zeros: none

Answers

9514 1404 393

Answer:

  D) y-intercept: (0, -10); vertex: (2, -2); zeros: none

Step-by-step explanation:

The graph does not cross the x-axis, so there are no real zeros. It crosses the y-axis at (0, -10), so that is the y-intercept.

These observations match choice D.

Is this correct? If not which is correct?

Answers

wrong it’s 21 inches
3x28 divided 4 = 21 inches

find the slope of the line between (1,4) and ( 3 , 10 )

Answers

Answer:

3

Step-by-step explanation:

slope of line = gradient of line

= [tex]\frac{10-4}{3-1}[/tex]

= 3

The correct slope for your question is 3

What is the completely factored form of this expression? 9x^3y - 100xy

Answers

Answer:

xy(3x+10)(3x-10)

4 in.
7 in.
O 124 6 in
87.9 in
O 97.5 in
O 78.9 in
5
6
7

Answers

Answer:

v=3.14 r 2 h

3.14 (2)(2)(7)= 87.9

Answer:

The answer for the Volume is 87.9 to 1d.p or 88in³ to the nearest tenth

Step-by-step explanation:

Volume of a cylinder =pir²h

r=d/2=4/2=2in

V=3.14×2²×7

V=3.14×4×7

V=87.92in³

V=87.9in³ to 1d.p

V=88in³ to the nearest tenth

An airplane flying at an altitude of 37,000 feet is still A horizontal distance of 100 miles (100 miles = 5280 ft) from the airport. What angle of depression does the airplane need to use to reach the runway?

Answers

Given :

An airplane flying at an altitude of 37,000 feet is still A horizontal distance of 100 miles (100 miles = 5280 ft) from the airport.

To Find :

What angle of depression does the airplane need to use to reach the runway?

Solution :

Let, angle of depression is [tex]\theta[/tex] .

So,

[tex]tan\ \theta = \dfrac{ Altitude \ in \ which \ plane \ is \ flying}{Horizontal \ Distance}\\\\tan \ \theta = \dfrac{37000}{5280}\\\\tan \ \theta = 7.00\\\\\theta = tan^{-1} 7\\\\\theta = 81.87^o[/tex]

Hence, this is the required solution.

Big math test I need help if I don’t I fail

Answers

5 give Brainly then I’ll help with all the other ones

How many different 4-digit PIN codes are there that only include the digits 5, 9, 6 and 2?

Answers

Answer:

256

Step-by-step explanation:

The digits can only be one of four numbers.

4*4*4*4 = 4^4 = 256

If point A, having
coordinates (p, 3) and
point B, with coordinates
(6, p) lie on a line having
a slope of 2, what is the
value of p?

Answers

gradient or slope=y2 -y1

x2 - x1

so for A, p is x1 and 3 is y1..

For B, 6 is x2 and p is y2

2= p - 3

6 - p

2 ( 6 - p) = p - 3

12 - 2p = p - 3

-2p + p = -3 - 12

-p = - 15

p = 15

A ball is thrown from an initial height of 4 feet with an initial upward velocity of 23 f/s. The ball's height h (in feet) after t seconds is given by the following. Find all values of t for which the ball's height is 12 feet.

Answers

Answer:

Time taken = 0.85 and 0.59 (Approx.)

Step-by-step explanation:

Given:

Initial height = 4 feet

Initial upward velocity = 23 f/s

Equation;

h = 4 + 23t - 16t² for h = 12 feet

Find:

Time taken

Computation:

h = 4 + 23t - 16t² for h = 12 feet

12 = 4 + 23t - 16t²

16t² -23t + 8 = 0

t = [-b±√b²-4ac] / 2a

t = [23±√23²-(4)(16)(8)] / 2(16)

t = [23±√529-512] / 32

t = [23±4.12]/32

Time taken = 0.85 and 0.59 (Approx.)

What is the common ratio of the sequence −8, 12,−18, 27, ...

Answers

Answer:

-3/2

Step-by-step explanation: Divide 12 by 8 and you get 3/2. Since the sign alters, the ratio is negative.

Suppose the speeds of cars along a stretch of I-40 is normally distributed with a mean of 70 mph and standard deviation of 5 mph. Use the 68-95-99.7 rule to answer the following questions.
(a) Approximately what percent of cars are travelling between 65 and 75 mph? percent
(b) If the speed limit on this stretch of highway is 65 mph, approximately what percent of cars are traveling faster than the speed limit? percent
(c) What percent of cars are traveling at a speed greater than or equal to 80 mph? (Answer to one decimal place.)
(d) What percent of cars are traveling at a speed greater than 80 mph? (Answer to one decimal place.) percent
(e) 95% of cars are traveling between what two speeds? (Answer to two decimal places) Between mph and mph

Answers

Answer:

a) 68%.

b) 84%.

c) Approximately 2.5% of cars are traveling at a speed greater than or equal to 80 mph.

d) Approximately 2.5% of cars are traveling at a speed greater than or equal to 80 mph.

e) Between 60 mph and 80 mph.

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean of 70 mph, standard deviation of 5 mph.

(a) Approximately what percent of cars are travelling between 65 and 75 mph?

70 - 5 = 65

70 + 5 = 75

Within 1 standard deviation, so approximately 68%.

(b) If the speed limit on this stretch of highway is 65 mph, approximately what percent of cars are traveling faster than the speed limit?

The normal distribution is symmetric, which means that 50% of the measures are below the mean, and 50% are above.

65 is one standard deviation below the mean, so of the cars below the mean, 68% are above 65 mph.

0.68*50% + 50% = 34% + 50% = 84%.

84%.

(c) What percent of cars are traveling at a speed greater than or equal to 80 mph?

80 = 70 + 2*10

2 standard deviations above the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean. Due to the symmetry of the normal distribution, of the other 5%, 2.5% is at least 2 standard deviations below the mean and 2.5% is at least 2 standard deviations above the mean. Then:

Approximately 2.5% of cars are traveling at a speed greater than or equal to 80 mph.

(d) What percent of cars are traveling at a speed greater than 80 mph?

Same as item c, as in the normal distribution, the probability of an exact value is considered to be 0.

(e) 95% of cars are traveling between what two speeds?

Within two standard deviations of the mean.

70 - 2*5 = 60 mph

70 + 2*5 = 80 mph.

Between 60 mph and 80 mph.

Solve 3/4w≤24 Graph the solution

Answers

Answer:

w<32

Step-by-step explanation:

Chase is 7 years older than Zoe. In 4 years the sum of their ages will be 41. How old is chase now?

Answers

Answer:

Chase would be 24 years old

A planet rotates through one complete revolution every 26 hours. Since the axis of rotation is perpendicular to the equator, you can think of a person standing on the equator as standing on the edge of a disc that is rotating through one complete revolution every 26 hours. Find the angular velocity of a person standing on the equator.

Answers

Answer:

23.5 degree stands tap of the floor

Eight less than the product of three and a number is twenty two

Answers

Answer:

let x represent the missing number

3x-8=22

3x=22+8

3x=30

3x/3=30/3

x=10

Step-by-step explanation:

hope this is helpful

Answer:

3x - 8 = 22

Step-by-step explanation:

always use x as "the number"

remember product means multiply!

8 less than the product of three and a number

3x - 8

lastly, "is 22"

"is" means equals

3x - 8 = 22

I hope this helps!!

what is the slope of a line between (-4,14) and (-16,8)

Answers

Answer:

[tex] \frac{1}{2} [/tex]

Step-by-step explanation:

slope :

[tex]slope \: = \: \frac{y2 - y1}{x2 - x1} = \frac{8 - 14}{ - 16 - - 4} = \frac{ - 6}{ - 12} = \frac{1}{2} [/tex] = 0.5

(08.02 MC)

A pair of equations is shown below:

y = 2x − 1
y = 4x − 5

Part A: In your own words, explain how you can solve the pair of equations graphically. Write the slope and y-intercept for each equation that you will plot on the graph to solve the equations. (6 points)

Part B: What is the solution to the pair of equations? (4 points)

Answers

Answer:

Complete y = Mx + b

Step-by-step explanation:

write the equation in slope intercept form for the line that passes through the point (1,2) and has a slope of -5

Answers

Answer:

y = -5 × 1 + 2

Step-by-step explanation:

y = y, m = slope, x = x point given (1), b = y point given, unless a zero (2)Formula - y = mx + bPlug it iny = -5 × 1 + 2

A sum of J$300 is divided in the ratio 2 : 3. Calculate the amount of the LARGER share. ​

Answers

9514 1404 393

Answer:

  J$180

Step-by-step explanation:

The ratio of the larger share to the total is ...

  3 : (2 +3) = 3 : 5

Then the larger share is ...

  (3/5)(J$300) = J$180

Calculate the remaining values:c d =​

Answers

Step-by-step explanation:

of what ? there is nothing here to work with.

Answer: C = 12 D = 8

Step-by-step explanation:

A study on the latest fad diet claimed that the amounts of weight lost by all people on this diet had a mean of 23.2 pounds and a standard deviation of 6.6 pounds. Step 2 of 2 : If a sampling distribution is created using samples of the amounts of weight lost by 65 people on this diet, what would be the standard deviation of the sampling distribution of sample means

Answers

Answer:

The standard deviation of the sampling distribution of sample means would be 0.8186.

Step-by-step explanation:

We are given that

Mean of population=23.2 pounds

Standard deviation of population=6.6 pounds

n=65

We have to find the standard deviation of the sampling distribution of sample means.

We know that standard deviation of the sampling distribution of sample means

=[tex]\frac{\sigma}{\sqrt{n}}[/tex]

Using the formula

The standard deviation of the sampling distribution of sample means

=[tex]\frac{6.6}{\sqrt{65}}[/tex]

[tex]=0.8186[/tex]

Hence,  the standard deviation of the sampling distribution of sample means would be 0.8186.

Someone please help on with these problems

Answers

I suggest you using for those problems!

Before it can be used, an 18-ounce container of liquid fertilizer must be mixed with 36 ounces of water. What fraction of fertilizer is in the final mixture? (type a simplified fraction)​

Answers

Answer:

1/3

Step-by-step explanation:

18 oz fertilizer to 36 oz water will make 18+36 = 54 oz of liquid

18/54 , simplify by 2

9/27, simplify by 9

1/3

Suppose a triangle has sides 1,
and 1. Which of the following must be true?
A. The triangle in question is a right triangle.
B. The triangle in question may or may not be a right triangle.
C. The triangle in question S not a right triangle.
SUBMIT

Answers

9514 1404 393

Answer:

  B. The triangle in question may or may not be a right triangle

Step-by-step explanation:

The length of the third side of the triangle may have any measure between 0 and 2. The triangle will only be a right triangle if the third side has length √2.

The triangle may or may not be a right triangle.

Line m is intersected by line t, as shown in the diagram below.
Based on the diagram, which of the following equations must be true?
a mz1+ m22 = 180°
b. m21+ m23 = 180°
C. m2 2 + m23 = 90°
d. m2 2 + m 24 = 90°

Answers

Answer:

Step-by-step explanation:

Only (a) sum of angles 1 and 2 = 180°  is true.

Answer:

a is the best answer

Step-by-step explanation:

mz1+m22=180°

Which equation best represents the relationship between x and y in the graph?

I’ll give brainliest

Answers

one equation could be y=-3/4x-3

Elegir
De acuerdo a las propiedades básicas de los triángulos ¿Cuánto suman los punto
ángulos internos de un triángulo?
180°
X
360°

Answers

Answer:

180°

Step-by-step explanation:

Una de las propiedades básicas de los triángulos, nos dice que para todo triángulo, la suma de los 3 ángulos internos es siempre igual a 180°.

Esto lo podemos comprobar si trazamos una regla paralela a uno de los lados que pase por el vértice opuesto a ese lado.

Podemos ver que el ángulo generado por una línea recta (un ángulo llano, es decir de 180°) es formado por el ángulo correspondiente al vértice que corta la línea y a dos ángulos de igual medida que los otros ángulos internos del triángulo.

Esto se puede observar en el dibujo de abajo (aunque el dibujo no sea muy prolijo, es suficiente para entender la idea).

What transformation is shown below??

Answers

The correct answer is A. Translation

Answer:

translation

Step-by-step explanation:

a translation. a translation is where the figure is moved, but not rotated or reflected.

A TV repair service company has a seasonal demand for its service,and there is a general shortage of skilled TV repair persons.Which one of the following is a capacity production planning alternative suitable for this situation?
A) Hire and lay off workers to match the demand requirements.
B) Increase the backlog for short-term demand surges.
C) Offer reduced prices during the slack season.
D) Build anticipation inventories.

Answers

Answer: increase the backlog for short term demand surges

Step-by-step explanation:

Since the TV repair service company has a seasonal demand for its service,and there is a general shortage of skilled TV repair persons, the capacity production planning alternative that's suitable for this situation will be to increase the backlog for short-term demand surges.

Offering reduced prices during the slack season isn't appropriate as this will lead to a reduction in revenue. Building anticipation inventories is also wrong as there may be differences in the forecast made.

The correct option is B.

Other Questions
What plasma membrane component can be either found on its surface or embedded in the membrane structure? Bastiat said that as a country moves from a proper form of government to a country that passes laws that are unjust it grows - but not in the right way. He compare the growth to a plant, and say it will move from Protectionism, to ___________ and then finally to Communism. What is in the shape of a triangular pyramid and has a height of 10 inches the area of the base of the container is 12 in. what is the volume of the figure actually inches Harry buys 6 yards of rope to make a swing. Lenny spends $16 on rope.How much do the two boys spend in all? Use the periodic table to identify the element indicated by each electron configuration by typing in thechemical symbol for the element. What reference source would you use to find an antonym for the word bizarre"? A bag contains 4 yellow, 2 red, and 6 green marbles. two marbles are drawn. the first is replaced before the second is drawn. a random variable assigns the number of red marbles to each outcome. calculate the expected value of the random variable.a. 0.67c. 0.17b. 0.56d. 0.33 What is the name of the shape depicted in the graph below?A. LimaonB. LemniscateC. RoseD. Cardioid Dan is a nature photographer who wants to share his pictures on his blog site. He wants to retain the high quality of the pictures, regardless of file size. Which file format is best suited for this purpose? who is popularly known as the father of economics contractor decided to bid for a major commercial project. The total price of her bid is $10 million. Estimate the total cost of estimating and preparing the bid proposal. what is the definition of a sheet metal tab? Facts, statistics, numerical data, quotations, specific examples, and expert opinions that support a claim are called:reasonevidencerebuttalstructural element Red hair, blue eyes, and height are all examples of... How do I find the length This mathematical model describes the changes that occur in a sample ofwater as its temperature increases. Use this model to predict what willhappen to the motion of the molecules in a sample of water if the heat sourceis removed.200Cvaporization150Cmelting100CTemperature (C)water vapor50Cliquid water0Cice-50C102050607030 40Time (min)A. The molecules will stop moving.B. The molecules will begin moving more quickly.C. The molecules will begin moving more slowly.D. The motion will change very little. Find all angles, o Pls help me simplify thisss use the distributive property to simplify the expression 1/5(2a-15b+5/6c)+7b. Take notes while you listen to the audio. Then answer the following question.Cul es la idea principal de este pasaje?La patata es otro nombre por la papa.La vainilla se origin en Mxico.El mundo sera muy diferente sin los productos de Espaa.Hay varios ingredientes populares en el mundo que vinieron de las Amricas.