You have 900-grams of an an unknown radioactive substance that has been determined to decay according to D ( t ) = 900 e − 0.002415 ⋅ t D ( t ) = 900 e - 0.002415 ⋅ t where t t is in years. How long before half of the initial amount has decayed?

It will take __ years for half of the initial amount to decay. (Round to 1 decimal place)

Answers

Answer 1
now, the initial amount is 900 grams, so half of that will be 450 grams.

so, how long will it be, for D(t) to turn to 450 grams?

[tex]\bf D(t)=900e^{-0.002415t}\implies 450=900e^{-0.002415t} \\\\\\ \cfrac{450}{900}=e^{-0.002415t}\implies \cfrac{1}{2}=e^{-0.002415t}\\\\ -------------------------------\\\\ \textit{Logarithm Cancellation Rules}\\\\ log_{{ a}}{{ a}}^x\implies x\qquad \qquad {{ a}}^{log_{{ a}}x}=x\\\\ -------------------------------\\\\[/tex]

[tex]\bf log_e\left( \frac{1}{2} \right)=log_e\left( e^{-0.002415t} \right)\implies log_e\left( \frac{1}{2} \right)=-0.002415t \\\\\\ \cfrac{ln\left( \frac{1}{2}\right)}{-0.002415}=t\implies 287.0174661 \approx t[/tex]

Related Questions

Brainleiest What is the unit rate for 692.08 ft in 21.1 s? Enter your answer, as a decimal, in the box. ft/s

Answers

Answer:

Unit rate is [tex]32.9561[/tex] feet per second.

Step-by-step explanation:

Unit rate is a number where one quantity is represented so that the other quantity is 1.

So we can give the unit rate of this as number of feet per 1 second.

It has traveled 692.08 ft in 21.1 seconds.

We have to find how many feet it travels in 1 second.

Unit rate = Number of feet / Number of seconds

=[tex]\frac{692.08feet}{21.1seconds}[/tex]

=[tex]32.9561[/tex] feet per second

Answer: 32.8

Step-by-step explanation: ( I'd use my answer if I was you) :)

Given the following triangle, if c = 17 and a = 15, find the measure of A. 28° 41° 62°

Answers

I'm not sure if it's a right triangle, but if not then you can use side-angle-side (SAS). No wait we don't have an angle, so it must be a right triangle (has a 90° angle).
Using trig, a is the side opposite A, and c is the hypotenuse.
Therefore using SOH-CAH-TOA, sin < = O/H = opposite/hypotenuse:
So sin A = 15/17 = 0.882
[tex]So \: arcsin \: ( {sin}^{ - 1} ) \: of \: 0.882 \: = a[/tex]
A = 61.92° = 62°

Find the solution of the given initial value problem y'+2/ty=cost/t^2

Answers

[tex]y'+\dfrac2ty=\dfrac{\cos t}{t^2}[/tex]
[tex]t^2y'+2ty=\cos t[/tex]
[tex](t^2y)'=\cos t[/tex]
[tex]t^2y=\sin t+C[/tex]
[tex]y=\dfrac{\sin t+C}{t^2}[/tex]

What is the solution of the proportion 5/x+4=3/x-2

Answers

Solve the rational equation by combining the expressions and isolating the variable X so X= -1/3

solve the system by graphing or using a table 3x+y=5 x-y=7

Answers

3x+y=5
x -y=7
------------add
4x = 12
  x = 3

x-y=7
3 - y = 7
y = 3 -7
y = -4

answer
(3, -4)
[tex]3x+y=5;x-y=7[/tex]

Evaluate the expression. [6(22 + 4)2 − 2(19 + 3)2]0

Answers

[6*2 (22+4) - 2*2(19+3)]0
=[12(26)-4(22)]0
=[312-88]0
=[27456]0
=0

Answer:

the anwser is 1  so B)Step-by-step explanation:i just gottt it right on usa test prep

92 divided by 4 use partial and quotients to divide

Answers

The partial quotient is 23
Alright 4 goes into 9 2 times so subtract 8 from 9 which will give you 1

then bring the 2 beside the 1 this should now be 12

after you do that do 12/4 which will give you 3 so the answer you are looking for is 23 

Hope this helps you! ;)

Which unit would you use to measure the amount of water in a swimming pool mL, kg, L or cm

Answers

If you are talking the volume of the pool liters(L) would be the best form of measurement.
I believe the answer is C. Liters milliliters would take too long to count, kilograms is about mass / weight, and centimeters is how long something is..

Hope this helps!

Jay went to an amusement park. The park charges an entrance fee of $10.50 and $4.50 for every ride. Jay spent $46.50 on entrance fees and rides. Which fuction can be used to find the number of rides he went on?

Answers

The function to find the number of rides Jay went on is [tex]\( 10.50 + 4.50x = 46.50 \)[/tex]

Let x be the number of rides Jay went on.

The cost of the entrance fee is $10.50, and the cost per ride is $4.50. The total amount Jay spent is $46.50. The equation representing this scenario is:

[tex]\[10.50 + 4.50x = 46.50\][/tex]

To find the number of rides, you can solve for x:

1. Subtract the entrance fee from the total amount:

  [tex]\[ 46.50 - 10.50 = 36.00 \][/tex]

2. Divide by the cost per ride:

 [tex]\[ \frac{36.00}{4.50} = 8 \][/tex]

So, Jay went on 8 rides.

The function to find the number of rides x is:

[tex]\[f(x) = 10.50 + 4.50x\][/tex]

Setting this equal to the total expenditure ($46.50), the function to find x is:

[tex]\[10.50 + 4.50x = 46.50\][/tex]

In a right triangle, he measure of one acute angle is 3 times the sum of the other acute angle and 8, Find the measure of angle 1 and 2

Answers

Let the acute angles be x and y respectively.  x= 3(y+8).

The sum of the interior angles of a triangle is always 180 degrees.  Therefore, 90 + y + 3(y+8) = 180, and so y + 3y + 24 = 90  =>  4y= 66, and y = 66/4 = 16.5 degrees.

Let's check:  If we're right, then y + 3(y+8) = 90
                                                16.5 + 3(16.5 + 8) = 90  ?
                                                 Yes.  (check it yourself)

Thus, the 3 angles of this right triangle are 90, 16.5 and 73.5; they add up to 180 degrees.

The measure of angles 1 and 2 are 16.5 and 73.5 respectively.

The sum of the two acute angles is complementary.

Let the complementary acute angles be x and y

Since they form a right angle triangle, hence;

x  + y = 90 ............................. 1

If the measure of one acute angle is 3 times the sum of the other acute angle and 8, this is expressed as x = 3(y + 8)

Substitute the value of x into the equation 1 as shown:

3(y+8) + y = 90

3y + 24 + y = 90

4y + 24 = 90

4y = 90 - 24

4y = 66

y = 66/4

y = 16.5

Get the other acute angle:

x = 90 - y

x = 90 - 16.5

x = 73.5 degrees

Hence the measure of angles 1 and 2 are 16.5 and 73.5 respectively.

Learn more here: https://brainly.com/question/11828005

In ΔABC, BC = 4 centimeters, m∠B = m∠C, and m∠A = 20°. What is AC to two decimal places?

A.9.32 centimeters

B.10.01 centimeters

C.11.52 centimeters

D.12.09 centimeters

Answers

m<A = 20°
m<B = m<C = 80°

Law of Sines , in any triangle we have
a/sin A = b/sin B = c/sin c

4/sin20 = AC/sin80 = AB/sin80

now we can solve AC

4/sin20 = AC/sin80
AC = 4 (sin80)/ sin20
AC = 4(0.98) / (0.34)
AC = 3.92 / 0.34
AC = 11.52

answer

C.11.52 centimeters

Answer:

C.11.52 centimeters

Step-by-step explanation:

Given,

In triangle ABC,

BC = 4 centimeters, m∠B = m∠C, and m∠A = 20°.

Since, the sum of all interior angles of a triangle is supplementary,

⇒ m∠A + m∠B + m∠C = 180°

⇒ 20° + m∠B + m∠B= 180°

⇒ 2 m∠B = 160°

⇒ m∠B = 80°,

Now, By the law  of sines,

[tex]\frac{sin A}{BC}=\frac{sin B}{AC}[/tex]

By cross multiplication,

[tex]sin A\times AC = sin B\times BC[/tex]

[tex]\implies AC = \frac{sin B\times BC}{sin A}[/tex]

By substituting values,

[tex]AC=\frac{sin 80^{\circ}\times 4}{sin 20^{\circ}}=\frac{3.93923101205

}{0.34202014332

}=11.5175409663

\approx 11.52\text{ in}[/tex]

List all the factor pairs in the table factors of 25

Answers

1,5,25 are the factors
The factors are 1, 5, and 25

A bag contains 20 red tickets and 12 blue tickets. What is the probability of randomly selecting a blue ticket from the bag? A. 4/5 B. 3/11 C. 3/8 D. 1/2

Answers

Okay. So, there are 12 blue tickets and 20 red tickets, which makes 32 total tickets in the bag. 12/32 tickets in the bag are blue, and we can simplify that fraction. 12/32 is less than 1/2, so A and D are both eliminated. 12/32 is 3/8 simplified. There is 3/8 of a chance that a blue ticket will randomly be selected from the bag. The answer is C.

Ali's dog weighs 8 times as much as her cat. Together, the two pets weigh 54 pounds. How much does Ali's dog weigh?

Answers

Dog's weight = 48. That's the answer.

Ali's dog weighs 48 pounds.

We have,

Let's assume the weight of Ali's cat is represented by the variable "x".

According to the given information,

Ali's dog weighs 8 times as much as her cat.

Therefore, the weight of Ali's dog can be expressed as 8x.

We are also given that together the two pets weigh 54 pounds.

So we can set up an equation:

x + 8x = 54

Combining like terms:

9x = 54

To find the value of x, we divide both sides of the equation by 9:

9x/9 = 54/9

Simplifying:

x = 6

Therefore, Ali's cat weighs 6 pounds.

To find the weight of Ali's dog, we can substitute the value of x back into the expression for the weight of the dog:

Weight of the dog = 8x = 8 * 6 = 48 pounds

Thus,

Ali's dog weighs 48 pounds.

Learn more about expressions here:

https://brainly.com/question/3118662

#SPJ6

You buy a pair of jeans at a department store.

What is the percent of sales tax to the nearest tenth of a percent?

The price of the jeans includes a 60% markup. After the discount, what is the percent of markup to the nearest percent?

Answers

The price of the jeans before the discount is $24.99. The sales tax rate is 6.5%. The percent of markup after the discount is 27.7%.

The price of the jeans before the discount can be found by dividing the total cost by the markup percentage plus 100% and then multiplying by 100%.

So, the price of the jeans before the discount is (39.99 / 160) * 100 = 24.994375.

Next, to find the sales tax, multiply the subtotal by the sales tax rate.

The sales tax rate can be found by dividing the sales tax amount by the subtotal and then multiplying by 100%.

So, the sales tax rate is (1.95 / 29.99) * 100 = 6.502167.

To find the percent of markup after the discount, divide the difference between the total cost and the price before the discount by the price before the discount and then multiply by 100%.

So, the percent of markup after the discount is ((31.94 - 24.994375) / 24.994375) * 100 = 27.67322.

The probable question may be:

You buy a pair of jeans at a department store.

What is the percent of sales tax to the nearest tenth of a percent?

The price of the jeans includes a 60% markup. After the discount, what is the percent of markup to the nearest percent?

Department store

Jeans =39.99

Discount =-10.00

Subtotal =29.99

Sales tax=1.95

Total = 31.94

The formula for glue says to add 50ML
of hardener to each container of resin. How much hardener should be added to 15 containers of resin?

Answers

Since it's 50mL of hardener added in ONE container of resin, you multiply 50 and 15
50mL times 15= 750mL
Hope this helps.

Final answer:

To find out the total hardener needed for 15 containers of resin, multiply 15 by the amount per container, 50ML, which equals 750ML of hardener in total.

Explanation:

To calculate the total amount of hardener needed for 15 containers of resin, we use a simple multiplication. We have been given that each container requires 50ML of hardener. Therefore, we multiply the number of containers by the amount of hardener needed per container.

Calculation:
Number of containers × Amount of hardener per container = Total amount of hardener
15 containers × 50ML/container = 750ML

Thus, for 15 containers of resin, you would need to add a total of 750ML of hardener.

A​ golf-course architect has six linden​ trees, four white birch​ trees, and three bald cypress trees to plant in a row along a fairway. in how many ways can the landscaper plant the trees in a​ row, assuming that the trees are evenly​ spaced? the trees can be planted in nothing different ways.

Answers

Answer:

the trees can be planted 4200 ways

Step-by-step explanation:

Final answer:

The landscaper can plant the trees in a row in 864 different ways.

Explanation:

To find the number of ways the landscaper can plant the trees, we can use the concept of permutations. Since the trees are evenly spaced, the order in which they are planted matters. We have a total of 6+linden+trees, 4 white birch trees, and 3 bald cypress trees. To calculate the number of ways to arrange them in a row, we can multiply the number of available options at each position. So, the number of ways to plant the trees in a row is 6! * 4! * 3! = 864. Therefore, there are 864 different ways the landscaper can plant the trees in a row.

what is 5/6 - (2/3) = ?

Answers

First remove the parenthesis. 
5/6 - 2/3
Then we want the least common denominator which is 6 because 2 * 3 = 6.
Now we want to adjust the fractions based on our LCD.
So 5/6 - 2 * 2/6
Now since the denominators are equal we can combine the numerators.
So 5 - 2 * 2/6
First multiply 2 by 2 to get 4. Our expression then becomes 5 - 4/6 which translates to 1/6.
Hope this helps!
when you subtract 5/6 and 2/3 you would get an answer of :1/6

Which represents the first three terms of the sequence: a1 = 2 and an = 4(an-1)2? 2, 16, 1024
4, 16, 1024
2, 16, 32
4, 16, 32

Answers

[tex]\bf \begin{array}{ll} term&value\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ a_1&2\\\\ a_2&4(a_{n-1})^2\\ &4(a_{2-1})^2\\ &4(a_1)^2\\ &4(2)^2\\ &16\\\\ a_3&4(a_{3-1})^2\\ &4(a_2)^2\\ &4(16)^2 \end{array}[/tex]

A science fair poster is a rectangle
3
feet long and
2
feet wide. What is the area of the poster in square inches?

Answers

Hello There!

Write formula:
Area = l x w
Substitute values in:
Area = 3 x 2
Solve:
Area = 6ft².
Convert to Square inches:
6ft² = 864in²

Hope This Helps You!
Good Luck :) 

- Hannah ❤
1 ft = 12 inches

so 3 ft = 12 * 3 = 36 inches (length)
and 2 ft = 2 * 12 = 24 inches (width)

A = L * W
A = 36 * 24
A = 864 square inches <==

Rick works off commission. He earns 10 percent of all manufacturing equipment he sells. If he made a sale of $9,000, how much was his commission?

Answers

commission would be 9000 * 0.10 = 900

 he would make $900

In the last two years, Mari grew 2 1/4 inches, Kim grew 2.4 inches, and Kate grew 2 1/8 inches. Write the amounts they grew in order from least to greatest

Answers

First, let's turn the fractions into decimal form so you can see the answer, more clearly. 
2 [tex] \frac{1}{4} [/tex] = 2.25
2.4 = 2.4
2 [tex] \frac{1}{8} [/tex] = 2.125

Now, after looking at the decimals, we can see which decimals are the biggest. They would order, from least to greatest, like this. 
1)  2.4
2) 2.25
3) 2.125

I hope this helps!

Answer:

[tex]\text{Growth in Kate}<\text{Growth in Mari}<\text{Growth in Kim}[/tex]

Step-by-step explanation:

We are given the following information in the question:

Growth in Mari =

[tex]2\displaystyle\frac{1}{4}\text{ inches} = \frac{2\times 4 + 1}{4} = \frac{9}{4} = 2.25\text{ inches}[/tex]

Growth in Kim =

2.4 inches

Growth in Kate =

[tex]2\displaystyle\frac{1}{8}\text{ inches}= \frac{2\times 8 + 1}{8} = \frac{17}{8} = 2.125\text{ inches}[/tex]

Growth in order from least to greatest:

[tex]2.125<2.25<2.4\\\text{Growth in Kate}<\text{Growth in Mari}<\text{Growth in Kim}[/tex]

in six years, clem kadiddlehopper will be 5 times as old as he was 26 years ago how old is he now?

Answers

x=clem's age now
in 6 years, he will be x+6 years old
that is 5 times as old as 26 years ago or when he was x-26 years old

so
x+6=5(x-26)
distribute the 5
x+6=5x-130
minus x both sides
6=4x-130
add 130 from boths ides
136=4x
divide both sides by 4
34=x
x=34
he is 34 now
Final answer:

The question involves setting up an equation to determine Clem Kadiddlehopper's current age based on his age in six years and 26 years ago. By solving the equation x + 6 = 5(x - 26), we find that Clem is currently 34 years old.

Explanation:

Explanation:

The question asks us to determine Clem Kadiddlehopper's current age based on information about his age in future and past years. Let's define Clem's current age as x years old.

In six years, he will be x + 6 years old. It is stated that in six years, Clem will be five times as old as he was 26 years ago. Since 26 years ago he was x - 26 years old, we can write the equation: x + 6 = 5(x - 26).

To find Clem's age, we will solve the equation:

x + 6 = 5(x - 26)x + 6 = 5x - 1304x = 136x = 34

Therefore, Clem Kadiddlehopper is currently 34 years old.

If the CPI (consumer price index) of 141 increased 8.3 % this year. What was the end of year CPI?

Answers

If the CPI increased by 8.3%, therefore this means that there was a fractional increase of 0.083. So amount increased is:

 

CPI increase = 141 * 0.083 = 11.703

 

Therefore the end of year CPI is the sum of the original and the increase:

 

end of year CPI = 141 + 11.703 = 152.703

 

Answer:

152.703



Hannah charges an hourly babysitting fee of $6 for two children, $7 for three children, and $8 for four or five children.


Which is true about the table when c = the number of children and f = the fee per hour?



c 1 2 3 4 5
f 6 6 7 8 8




The relationship is not linear between c and f.

The relationship is linear between c and f.

The relationship is not linear for c and linear for f.

The relationship is linear for c but not f.

Answers

The given table is
c  1  2  3  4  5
f  6  6  7  8  8

c = the number of children
f = the fee per hour

The given information is
f = $6 when c = 2;
f = $7 when c = 3;
f = $8 when c = 4 or c = 5.

A graph of the data is shown below.
Notice that the fee for 1 child was not provided, but it was provided in the table.

Let us examine the given answers.
(a) The relationship is not linear between c and f.
     TRUE
(b) The relationship is linear between c and f.
     FALSE
(c) The relationship is not linear for and linear for f.
    FALSE
(d) The relationship is linear for c but not f.
    FALSE

Answer: The relationship is not linear between c and f.

a person leaves their house to go to the store. it takes 15 minutes at 12 mph to get to the store. They return home at 31 mph. What is the average rate of the speed for the entire trip?

Answers

[tex]\bf \cfrac{\stackrel{speed~forth}{12}+\stackrel{speed~back}{31}}{\stackrel{interval~forth}{1}+\stackrel{interval~back}{1}}\implies \cfrac{43}{2}\implies 21.5mph\textit{ on average}[/tex]

A shirt company has 3 designs that can be made with short or long sleeves. there are 6 color patterns available. how many different types of shirts are available from this company?

Answers

I think is:
[tex]3 \times 6 = 18[/tex]

Answer: 36 Types

Step-by-step explanation:

3 designs and 6 color options so that would be

3 x 6 = 18

they also have the option of either long or short sleeve so that would be

18 x 2 = 36

Solve this expression 5(4x-13).

Answers

The expression can be simplified down to 20x-65
5(4x - 13)

Simplify.

(5 · 4x) + (5 · -13)

Simplify.

20x + (-65)

Get rid of the parenthesis.

20x - 65

~Hope I helped!~

Lorenzo bought 15 / 16 pounds of ground beef.He wants to make hamburgers that weigh 3 / 16 pounds each.How many hamburgers can he make?

Answers

If each burger is 3/16. You can do 15 divide 3. The answer is 5

FIrst of all, i recommends you to do a model. Of 15/16 and 3/16 then compare them and take away the same denominators. What would you get? 15 and 3 so you would divide both of them And you will get 5 as your answer, remember to do an explanation on how you got it. :)

Where e is the region that lies inside the cylinder x2 + y2 = 16 and between the planes z = −4 and z = 1?

Answers

Final answer:

The region e refers to the inside of a cylinder defined by x² + y² = 16 and between the planes z = -4 and z = 1. It represents a three-dimensional space bounded both radially, by the cylinder, and vertically, by the planes.

Explanation:

The region described in the question is a cylindrical volume in three-dimensional space. To visualize this region, we remember that the cylinder is defined by the equation x2 + y2 = 16, which is the set of points in the xy-plane that are at a distance of 4 from the origin (since the radius is √16 = 4). This cylinder extends indefinitely in the positive and negative z-directions.

The planes z = -4 and z = 1 act as boundaries in the z-direction, trimming the cylinder down so that we're only considering the portion of the cylinder between these two planes. Thus the region e of interest is the set of points inside the cylinder that lie at a height between z = -4 and z = 1.

This type of region is common in problems involving volume calculations, especially when using integral calculus to determine the volume of the shape or when analyzing physical phenomena like fluid flow or electric fields within prescribed bounds.

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