half-life of Po-210 is 140 days. If the initial mass of the sample is 5
kg, how much will remain after 420 days.

Answers

Answer 1

Answer:

[tex]0.625kg[/tex]

Step-by-step explanation:

we are given half-life of PO-210 and the initial mass

we want to figure out the remaining mass after 420 days

in order to solve so we can consider the half-life formula given by

[tex] \displaystyle f(t) = a {0.5}^{t/T} [/tex]

where:

f(t) is the remaining quantity of a substance after time t has elapsed.a is the initial quantity of this substance.T is the half-life

since it halves every 140 days our T is 140 and t is 420. as the initial mass of the sample is 5 our a is 5

thus substitute:

[tex]\displaystyle f(420)=5\cdot{0.5}^{420/140}[/tex]

reduce fraction:

[tex]\displaystyle f(420)=5\cdot{0.5}^{3}[/tex]

By using calculator we acquire:

[tex]\displaystyle f(420)=0.625[/tex]

hence, the remaining sample after 420 days is 0.625 kg


Related Questions

How do I solve these problem?

Answers

Answer:

- 199

Step-by-step explanation:

7.

a1 = 25

d = - 16

15th term is t15.

Formula : -

an = a + ( n - 1 )d

t15

= 25 + ( 15 - 1 ) - 16

= 25 + 14 ( - 16 )

= 25 + ( - 224 )

= 25 - 224

= - 199

What is the distance between (-2,-8)(7,-3)

Answers

Answer:

[tex]\sqrt{106}[/tex] or 10.29563

Step-by-step explanation:

Use the distance formula to determine the distance between the two points.

[tex]d = \sqrt{(x_{2} -x_{1})^{2} + (y_{2} - x_{1})^{2} }[/tex]

d = distance

[tex](x_{1}, y_{1})[/tex] = coordinates of the first point

[tex](x_{2}, y_{2})[/tex] = coordinates of the second point

Answer:

[tex]\displaystyle d = \sqrt{106}[/tex]

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Algebra I

Coordinates (x, y)

Algebra II

Distance Formula: [tex]\displaystyle d = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

Step-by-step explanation:

Step 1: Define

Identify

Point (-2, -8)

Point (7, -3)

Step 2: Find distance d

Simply plug in the 2 coordinates into the distance formula to find distance d

Substitute in points [Distance Formula]:                                                         [tex]\displaystyle d = \sqrt{(7--2)^2+(-3--8)^2}[/tex][√Radical] (Parenthesis) Subtract:                                                                   [tex]\displaystyle d = \sqrt{(9)^2+(5)^2}[/tex][√Radical] Evaluate exponents:                                                                       [tex]\displaystyle d = \sqrt{81+25}[/tex][√Radical] Add:                                                                                                 [tex]\displaystyle d = \sqrt{106}[/tex]

HELP PLEASE!! a space station orbits earth at a rate of 57 miles every 3 seconds
Write the space stations rate of change

Answers

Answer:

i think its every 90 minutes but I could be wrong.

Step-by-step explanation:

A cake weighs 215 g and is shared equally between five people. What weight of cake does each person receive?

Answers

Answer: 43 g

Step-by-step explanation: For 215 to be divided equally between five people the equation should be set up as 215/5, which equals 43 g for each person.

You just have to divide the weigh of the cake by the number of people that’ll be sharing it

For example 215g dived by 5 is 43g
Therefore each person receive 43g of the cake.


(God bless you)

What is the value?
I’m confused lolz {}:

Answers

Answer:

14

Step-by-step explanation:

1/9(3)^4+5

1/9*81+5

9+5

14 is your answer

Find the 93rd term of the arithmetic sequence -6,13,32...

Answers

Answer:

1742

Step-by-step explanation:

I am of the belief this is the right answer according to the arithmetic calculator.

please help will mark brainliest

Answers

6=68 and 8=112
This is Bc 1=112 and 1 and 4 are virtual angles so 4 would also equal 112. And 4 and 6 are supplementary angles, and supplementary angles always add up to 180, and since 4 is 112 you’d subtract 112 from 180 and you’d get 68, so 6=68 and 6 and 8 are also supplementary angles so 8 would be 112

i need help solving this math problem from my practice work

Answers

B is 27, your answer is 27

What is the value of x for this triangle.

Answers

Answer:

13

Step-by-step explanation:

you have to use Pythagorean Theorem which is

(a^2) + (b^2) = (c^2)

where a and be are the legs 45° from each other and c is the hypotenuse.

so just plug in the numbers

5^2 + 12^2 = c^2

25 + 144 = c^2

169 = c^2

now square root both sides to get rid of the square on c

root(169) = root(c^2)

13 = c

f(x) = 3^x-9. find the inverse of f(x). ASAP I NEED HELP LAST QUESTION AND 15 MINS LEFT

Answers

Answer:

A

Step-by-step explanation:

Given :

f(x) = ³√[ x - 9 ]

And we need to find the inverse of the given function. We can do it by Firstly Interchanging x and y.

So that ,

[tex]:\implies[/tex] f(x) = y

[tex]:\implies[/tex] y = ³√[ x - 9 ]

[tex]:\implies[/tex] x = ³√[ y - 9 ]

[tex]:\implies[/tex] x³ = y - 9

[tex]:\implies[/tex] y = x³ + 9

[tex]:\implies[/tex] f-¹(x) = x³ + 9

Hence option A is correct .

I just need help in this last question plsssss

Answers

Answer:

B) 0.8

Step-by-step explanation:

If events are said to be independent, then just multiply the probability of the first event by the second if they are supposed to be happening together.

P (A) * P (B) = 0.8 x 1 = 0.8

Melissa built a square pyramid out of sand. The base of the pyramid has a side length of 18 centimeters. The height of the pyramid is 26
centimeters.
What is the volume of the pyramid?
A. 624 cm3
B. 1,872 cm
C. 2, 808 cm
D. 4,212 cm
E. 8, 424 cm

Answers

Answer:

C. 2, 808 cm^3

Step-by-step explanation:

Given that

The base of the pyramid is 18 centimeters

And, the height of the pyramid is 26 centimeters

We need to find out the volume of the pyramid

As we know that

The volume of the pyramid is

= 1 ÷ 3 × base^2 × height

= 1 ÷3 × 18^2 × 26

= 2,808 centimeter^3

Hence, the correct option is c.

i need help asap RIGHT ANSWERS ONLY PLEASE !!!!!!’n

Answers

Answer:

hey, the answer is 9π m²

What is -3x-y=-24 if Y =3x

Answers

Answer:

x= 4 and y= 12

Step-by-step explanation:

solve by substitution

hope this helps :D

I need help. NO links or I will report.

Answers

Answer:

30

Step-by-step explanation:

Well I think that this is a line, and so the angle is 180. The other line is 90 which is half of 180. It leaves 90 left. then all you have to do is solve the equation 3x=90 (x+2x=3, 9-9=0) 90 divided by 3 is 30.

Simon leans a 20 ft ladder against the side of his house so that the base of the ladder is
5 ft from the house. About how high up the side of the house does the ladder reach?
Round to the nearest tenth of a foot?

Answers

The answer is 19.4
Most of the time when you try to find a missing length of a right triangle you use Pythagorean theorem. Pythagorean theorem is A squared plus B squared equals C squared. C squared is always going to be the longest length/diagonal line otherwise known as your hypotenuse. In this case the ladder is the hypotenuse. So instead of adding five squared +20 squared you’re going to square 20 and then subtract five squared to get the missing length which would be B squared and then you have to find the square root of B squared. So 20 squared is 4000. 5squared is 25 400-25 = 375 square root of 375 is about 19.4.

Please help I'm doing homework and its due at 1:00!

Answers

Your answer is correct it’s 4/33. You first have to convert the mixed number into an improper fraction. Then you’ll have 1/6/11/8 and then you will simplify the complex fraction. I hope that helps!

Mandy the elephant weighs 7,390 lbs her baby luna weighs 1492 how many more pounds does mandy weigh than luna

Answers

Answer:

5898

Step-by-step explanation:

7,390 - 1,492 = 5898

Plz help with this I don’t know what to do

Answers

Answer:

Just guessing here but would the bottom be 4,8,12,16,20 maybe since it is going by 4 then you do the same for the top since it is going by 3

Step-by-step explanation:

Answers:

Row One:  9,   15Row Two:  8, 16, 20

Input the numbers only in each box. So that means you won't type in a comma.

The least common denominator is  12

=======================================================

Explanation:

Your teacher wants you to list the multiples of each denominator.

The multiples of 3 are: 3, 6, 9, 12, 15The multiples of 4 are: 4, 8, 12, 16, 20

The values in bold are what will go in the boxes in those first two rows.

The least common denominator is 12 because it is the smallest thing found in common in the two lists above. In other words, 12 is the LCM (least common multiple) of 3 and 4. Note how 3*4 = 12. This works because 3 and 4 do not have any common factors between them other than 1.

The LCD (least common denominator) is the LCM of the denominators. The LCD is useful for when you want to add or subtract fractions. The denominators must be the same for you be able to add or subtract them.

PLS ILL MARK BRAINLIEST (100 points)

Answers

Answer:

For part A:

9x² - 36x + 36 = 0

9(x² - 4x + 4) = 0

9(x-2)(x-2) = 0

Radicand = Discriminant = 36² - 4(9)(36) = 0

there is 1 real zero that repeats itself)

zero is x=2.

Use factoring. Factors of 7 are 1 and 7

2x²-9x+7 = 0

(2x-7)(x-1) = 0

2x-7 = 0 (x-1)=0

2x = 7x=1

x = 7/2

Your solutions are x = 1 and x = 7/2

Step-by-step explanation:

Another name for rate of change is slope.

true or false.

Answers

Answer:

True

Step-by-step explanation:

Answer:

True!

Step-by-step explanation:

“Rate of change” means the same as “slope.” If you are asked to find the rate of change, use the slope formula or make a slope triangle.

P(blue) someone plz help me

Answers

what is the question¿

Help please


Thanks <3

Answers

Answer:

answer in the screen shot provided

Please help I will give brainliest to the first correct answer!!!

Answers

The answer is square root of 72

The temperature in San Antonio, Texas is currently 77 degrees Fahrenheit and increasing by 3 degrees per hour. The current temperature in Mumbai, India is 92 degrees Fahrenheit and dropping by 2 degrees per hour. 1. When will the temperatures be the same? 2. What will that temperature be?​

Answers

Answer:

1)3 2)86

Step-by-step explanation:

3h+77=SA AND 92-2h=MB

3h+77=92-2h

-77. = -77

3h= 15-2h

+2h=+2h

5h=15

H=3

an event that cannot happen is

a certain
b possible
c impossible

Answers

an event that cannot happen is impossible
c. impossible
certain and possible are things that will or could potentially happen

how to solve x^2-4x=-12

Answers

x = 6 and x = -2

Step-by-step explanation:

Put the 12 to the other side

x^2 - 4x - 12 = 0

Now factor this out:

(x - 6)(x + 2) = 0

Therefore, the roots of this equation are

x = 6 and x = -2

Is the X^2 exponent ?

Which is the solution set of this equation? |x – 6| = 15 A. {-9, 21} B. {-15, 15} C. {9, 21} D. {-9, -21} E. {-6, 6}

Answers

Answer:

A. -9, 21

Step-by-step explanation:

Use m.a.t.h.w.a.y and you will get the answer!

Answer:

A

Step-by-step explanation:

| x-6| = 15 , check if this is true for the given x values

for x= -9 we have | -9-6| =  15 true

for x= 21 we have | 21 -6| = 15 true

so A is a solution set

for x= -15 we have | -15-6| =  15 false

so B is not a solution set

for x= 9 we have | 9-6| =  15 false

so C is not a solution set

for x= -9 we have | -9-6| =  15 true

for x= -21 we have | -21-6| =  15 false

so D is not a solution set

for x= -6 we have | -6-6| =  15 false

so E is not a solution set

Solve this system of equations by using the elimination method. 2x - 2y = 2. 5x + 2y = 12 (2, [?])​

Answers

Answer:

(2,12)

Step-by-step explanation:

mathpapa

Answer:

(2,1)

Step-by-step explanation:

Im really struggling with this, i need A on this test please help me!

Question 4 options:


The volume of the square pyramid is ___ cubic centimeters.

Answers

The volume of the square pyramid is 600cm^3

The volume of the square pyramid is 600cm^3

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