Arsenic-74 is used to locate brain tumors. It has a half-life of 17.5 days. 90 mg were
used in a procedure. Write an equation that can be used to determine how much of
the isotope is left after x number of half-lives.


How much would be left after 70 days?

Answers

Answer 1

After x half-lifes, the amount of the isotope is:

A(x*T) = 90mg*e{-x*ln(2)}

And after 70 days, there are 5.628 mg

What is the half-life?

We define the half-life as the time such that the inital amount of a given substance reduces to half of it.

If the half-life is T, the amount of the substance can be written as:

A(t) = a*e^{-λ*t}

Where λ = ln(2)/T.

and a is the initial amount.

In this case, T = 17.5 days, then:

λ = ln(2)/17.5 days = 0.0396 / day

And we also have a = 90mg

Then the exponential equation is:

A(t) = 90mg*e^{-t*0.0396 / day}

After x half-lifes, the amount of the isotope left is:

A(x*T) = 90mg*e^{-x*T*ln(2)/T} = 90mg*e^{-x*ln(2)}

And after 70 days the amount is:

A(70 days) = 90mg*e^{-70 days*0.0396 / day} = 5.628 mg

If you want to learn more about exponential decays, you can read:

https://brainly.com/question/11464095

Answer 2

Answer:

Y=90mg(0.5)^5


1.86 after 70 days

Step-by-step explanation:


Related Questions

Please help with one through three Brainliest to the correct in best answer

Answers

Answer:

1. Alike

2. Opposite

3. Common factor

Step-by-step explanation:

1. To have a positive number, you can only have alike signs, for example, any positive number times another positive number is always positive. The same is true for negative numbers multiplied by each other.

2. To have a negative number, there has to be one negative number and one positive number being multiplied together. Always. For example:

3 x -5 =-15

10 x -1 = -10

3. You can factor out a common factor to simplify a polynomial before you factor it.

A gas station sells motor oil in 2-liter bottles. The gas station sold 6 bottles of oil each day for 8 days.

How many liters of motor oil did the gas station sell in these 8 days?

Answers

Answer:

96 liters

Step-by-step explanation:

Two liters are in each bottle, so that means they sold 12 bottles of oil each day. Multiply that with 8 days to get the answer:

12 × 8 = 96

Ninety-six liters.

If the area of a circle is 64 pie square centimeters, then what is its radius

Answers

Answer:

8

Step-by-step explanation:

A=πr^2

64π=πr^2

since answer is in terms of pi, ignore the pi.

sqrt(64)=8

What is X?
(x+22) 2x
(Need help)

Answers

Answer:

nasa pic yung sagot

hope its help

What is the solution to the equation 6 m = 60?
m = 10
m = 50
m = 66
m = 360

Answers

Answer:

[tex]\displaystyle m = 10[/tex]

Step-by-step explanation:

[tex]\displaystyle \frac{60}{6} = \frac{6m}{6} \\ \\ \boxed{10 = m}[/tex]

I am joyous to assist you at any time.

Answer:

[tex]\sf{m=10}[/tex]

Step-by-step explanation:

The value of m must be found from one side of the equation in order to solve this problem.

6m=60

First, divide by 6 from both sides.

[tex]\sf{6m=60}[/tex]

[tex]\sf{\dfrac{6m}{6}=\dfrac{60}{6} }[/tex]

Then, solve it.

[tex]\boxed{{\sf{m=10}}}[/tex]

Therefore, the correct answer is m=10.

I hope this helps you! Let me know if my answer is wrong or not.

Define a polynomial that is a difference of squares. How do you know that it is the difference of squares? How is it factored?

Answers

Answer:

When an expression can be viewed as the difference of two perfect squares, i.e. a²-b², then we can factor it as (a+b)(a-b). For example, x²-25 can be factored as (x+5)(x-5). This method is based on the pattern (a+b)(a-b)=a²-b², which can be verified by expanding the parentheses in (a+b)(a-b).

Step-by-step explanation:

lol it’s on wassa name ;) mark me brainliest? Btw

Here you go, your equation should look a lot like this:

x²-16 -----> (x+4)(x-4).

2-y^2=-14 solve for y express answer as an integer or in simplest radical form

Answers

Answer:

8

Step-by-step explanation:

y^2=-16

y= -16/1 % 2/1

y=-16/1 % 1/2

y = 8

Answer:

y=4

Step-by-step explanation:

its -y^2=-16. square root both sides to get rid of the exponent and it gives you -y=-4 which is the same as y=4

look at pic please and answer

Answers

22 students which is the answer

There are 9 members on a board of directors. if they must elect a chairperson, a secretary, and a treasurer, how many different slates of candidates are possible? a. 504 c. 729 b. 84 d. 362,880

Answers

Answer:

A. 504

Step-by-step explanation:

on edge 2022

Answer:

A.

Step-by-step explanation:

EDG 2022

Rebecca is calculating her expected expenses for her week long trip to Thailand. Her plane ticket costs 22,885 baht, her lodging costs 15,307 baht, and she has set aside 29,071 baht for food and spending money. What is Rebecca’s total expense? a. 128,071 baht b. 67,263 baht c. 21,493 baht d. 9,121 baht.

Answers

Answer:

The answer is B because you add up the 3 expenses

Step-by-step explanation:

Add the three expenses

The total expected expense of Rebecca for her week long trip to Thailand is given by: Option B: 67,263 baht

How to calculate total expense?

Total expense shows the overall expense for the thing we're expending for. We add all the expenses to get the total expense.

For this case, we're given that:

Cost of plane tickets = 22,885 bahtCost of lodging = 15,307Cost for food and other expenses = 29,071

So, total expected expense is sum of all these expenses.

Total expected expense = 22885 + 15307 + 29071 = 67263 baht

Thus, the total expected expense of Rebecca for her week long trip to Thailand is given by: Option B: 67,263 baht

Learn more about addition here:

https://brainly.com/question/1709448

7(4-x) how do I do this problem

Answers

Answer:

28-7x

Step-by-step explanation:

You distribute 7 and 4 and 7 and the x

Hopes this helps.

k (a+b) = k*a + k*b

so

7 (4-x) = 7*4 + 7*(-x) = 28 - 7x



a kite is 50 m high when 200 m of sting is let out. what angle does the kite string make with the ground to the nearest tenth of a degree?

the angle between the kite string and the ground is ?

Answers

Check the picture below.

Make sure your calculator is in Degree mode.

I just need to fill the table out

Answers

Answer:

for cosine: 1, 0.97, 0.87, 0.71, 0.5, 0.26, 0..... for sine: 0, 0.26, 0.5, 0.71, 0.87, 0.97, 1.

Step-by-step explanation:

Calculator for Cos, reverse them for Sine.

Can the GCF of a pair of numbers ever equal one of the numbers? Explain how you know

Answers

Answer:

It can

Step-by-step explanation:

For example, the GCF of 44 and 22 is 22.

Yes. If one number which is small is the factor of other number, then the GCF will be the smaller number
Eg: 13, 26
13 is the factor of 26. 26= 13*2
So, GCF of 13 and 26 = 13


Jory's motorcycle travels at a constant rate of 18 miles in 45 minutes. What is the rate, in miles per hour,
that Jory is traveling?
A. 13
B. 18
C. 24
D. 26
please give explanation

Answers

Answer:

C. 24

Step-by-step explanation:

We should find how many miles Jory travels in 15 minutes first.

45 ÷ 15 = 3

18÷3=6

6 miles in 15 minutes

every hour has 60 minutes

60 ÷ 15 = 4

multiply 6 by 4 to find miles per hour

6×4=24

Michelle's keeping track of how much time she spends playing video games. She knows she gamed for a total of 60 hours during the past 3 weeks. She played 4 hours more during the 2nd week than the 1st week. Also, she played 2 hours less during the 3rd week than the 2nd week. How many hours did she spend playing video games during the 3rd week?

Answers

Answer:

I have no clue.

Step-by-step explanation:

Answer:

What is a appropriately

What is a Procedure

What is a Enthusiasm

What is a Conflict

What is a Technique

What is a Obtain

What is a conflict management

Need help with this pls

Answers

Answer:

Answer:

SORRY

Step-by-step explanation:

ANSWER

Step-by-step explanation:

Answer:

SORRY

Step-by-step explanation:

ANSWERAnswer:

SORRY

Step-by-step explanation:

ANSWER

What is the measure of the missing angle?

39 faren height plus 33 plus an unknown number to equal 180

Answers

Answer:

108

Step-by-step explanation:

39 + 33 + x = 180

To find the missing angle, we have to add together the two angles that are given and then subtract that from 180.

39 + 33 = 72

180 - 72 = 108

Therefore, our answer is 108 degrees.

I hope this helps! Have a lovely day!! :)

Find the volume of a pyramid with a square base, where the side length of the base is 16.6m and the height of the pyramid is 9.1 m. Round your answer to the nearest tenth of a cubic meter.

Answers

Answer:

Formula for volume of square pyramid:-

V = 1/3 x a^2 x h

Where 'a' is the length of one side of the base, and 'h' is the height.

Plug in our values, given that:

16.6m = side length of base.

9.1m = height of pyramid.

V = 1/3 x a^2 x h

V = 1/3 x 16.6^2 x 9.1

V = 1/3 x 275.56 x 9.1

V = 1/3 x 2507.596

V = 2507.596/3

V = 835.865, which rounds to 835.9 cubic meters.

Felipe just started collecting stamps. he has 36 stamps so far. His uncle Caro has 1,890 stamps in his collection. The number of stamps Carlos has is how many times the number Felipe has?

Answers

Answer:

52.5

Step-by-step explanation:

just divide bro it ain't that hard

Solve for x in the trig function

Answers

Step-by-step explanation:

cos(81) = x/sqrt(7)

x = sqrt(7)×cos(81) = 0.413886691...

An electrician has an income of $41,500. The income tax the electrician has to pay is 12%. What is the amount of income tax that the electrician has to pay? A) $3,840 B) $4,164 C) $4,980 D) $5,210

Answers

Answer:

he has to pay 4980$ in tax

Step-by-step explanation:

Answer:

This question was on my test and I got a 100 so its right

Step-by-step explanation:

I need help please provide the steps

Answers

Answer:

1/[tex]\sqrt{2}[/tex] - 1/4

Step-by-step explanation:

We can write 2[tex]\sqrt{8}[/tex] as 2*[tex]\sqrt{4}[/tex]*[tex]\sqrt{2}[/tex]

That becomes 4[tex]\sqrt{2}[/tex], since the square root of 4 is 2 (±2, to be exact)

(4/(4[tex]\sqrt{2}[/tex])  - ( [tex]\sqrt{2}[/tex]/4[tex]\sqrt{2}[/tex])

1/[tex]\sqrt{2}[/tex] - 1/4

Let n be a positive integer. z^n is the set of all lists of length n whose
entries are in z. prove that z^n is countable. (hint: find a bijection
between z^(n−1) × zand z^n and then use induction.)

Answers

Positive integer is the best because it just is

( Pls help ASAP) Will give 20 points if you answer 2 questions))

Answers

Answer:

1. -3          2. y=-1

Step-by-step explanation:

Edmond buys 4/5 of a kilogram of butterscotch chips and 5 kilograms of milk chocolate chips.
How much does he spend?
milk chocolate chips
$1 per kg
white chocolate chips
$2 per kg
dark chocolate chips
$3 per kg
butterscotch chips
$1 per kg
semisweet chocolate chips
$2 per kg

Answers

He spent $5.80.

1 x 4/5 = 0.8
1 x 5 = 5

what energy changes or causes

Answers

Answer: Nearly all thermal energy on Earth originates from the sun and radiates to the surface of our planet, traveling in the form of electromagnetic waves, such as visible light. Materials on Earth then absorb these waves to be used for energy or reflect them back into space. In an energy transformation, energy changes form.

Step-by-step explanation:

What is the Inverse of function ?
f(x) = (3-x)/7

Answers

Answer:

y = -7x+3

Step-by-step explanation:

We can write the function as

y = (3-x) / 7

To find the inverse of this function we have to do 2 things

a. change x with y and y with x  and

b. find the y

a. y = (3-x) / 7, change x with y and y with x  

   x = (3-y) / 7, multiply both sides by 7

b.     7x = 3-y, subtract 3 from both sides

      7x-3 = -y, multiply both sides by -1

      -7x+3 = y

The inverse function of

f(x) = (3-x)/7  is [tex]f^{-1} (x) = -7x + 3[/tex]

pls help with this brain boggling work
:)​

Answers

Answer:

$10/hour

Step-by-step explanation:

The graph shows the relation between the number of hours Hachi works to the money he earns at his job

Solving

Pay rate = Money earned / Number of hoursPay rate = 10/1 = 20/2 = 30/3 = .... ⇒ $10/hour

Take two points and find slope

(0,0)(1,10)

Slope

m=10-0/1-0m=10/1m=10

Pay rate 10$/h

What is one thing you would not do when finding the question in a word problem?
A. Look for a problem similar to the word problem you are trying to solve.
B. The question may not be directly stated.
C. So you can understand what the facts are in the word problem.
D. To define your strategy or game plan to solve the word problem.
ill give brainliest and 100 points

Answers

Answer:

A. Look for a problem similar to the word problem you are trying to solve is the answer.

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