Element X is a radioactive isotope such that every 30 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 100 grams, how long would it be until the mass of the sample reached 64 grams, to the nearest tenth of a year?

Answers

Answer 1

Answer:

19.3 years

Step-by-step explanation:

Given that the initial mass of a sample of Element X is 100 grams,

The formula is given as:

N(t) = No × (1/2) ^t/t½

Element X is a radioactive isotope such that every 30 years, its mass decreases by half.

N(t) = Mass after time (t)

No = Initial mass = 100 grams

t½ = Half life = 30 grams

N(t) = 100 × (1/2) ^t/30

How long would it be until the mass of the sample reached 64 grams, to the nearest tenth of a year?

This means we are to find the time

N(t) = 100 × (1/2) ^t/30

N(t) = 64 grams

64 = 100(1/2)^t/30

Divide both sides by 100

64/100 = 100(1/2)^t/30/100

0.64 = (1/2)^t/30

Take the Log of both sides

log 0.64 = log (1/2)^t/30

log 0.64 = t/30(1/2)

t = 19.315685693242 years

Approximately = 19.3 years


Related Questions

The diameter of a circle is 20 meters. What is the circumference?

Answers

Step-by-step explanation:

C≈62.83m

Using the formulas

C=2πr

d=2r

Solving forC

C=πd=π·20≈62.83185m

Find two numbers that multiply to -36 and add to -5.

Type below no links

Answers

Answer:

-6 times 6= -36

-36 + 31 = 5

Step-by-step explanation:

cuanto es 1+1
respuestas originales
gracias

Answers

Answer:

Step-by-step explanation:

It’s 2

Answer:

[tex]1 + 1 = 2[/tex]

[tex]espero \: haberte \: ayudado[/tex]

3. Here are diagrams that represent 0.137 and 0.284.
tenths
hundredths
thousandths
a. Use the diagram to find the value of. Explain your reasoning.
b. Calculate the sum vertically.
0.1 3 7
0.2 8 4
+

Answers

if you’re just adding shouldn’t it be .421?

12. The variable in the expression 9x + 63 is ? * A. =
B. 9
C. x
D. 36​

Answers

Answer:

C. x is the variable

Step-by-step explanation:

easy...

C. X is the variable expression

100 POINTS PLEASE ANSWER QUICK

Answers

Answer:

c the answer is c

Step-by-step explanation:

Answer:

The answer is B

Step-by-step explanation:

Mark as Brainllest

The radius of the base of a cone is 4 inches. The slant height of the cone is
6 inches. Which is closest to the surface area of the cone?
F 75 sq in.
100 sq in.
H 126 sq in.
J 188 sq in.

Answers

Question:-

The radius of the base of a cone is 4 inches. The slant height of the cone is 6 inches. Which is closest to the surface area of the cone ?

Answer:-

Given:-

[tex] \bullet [/tex] Radius (r) of the base of a cone is 4 inches.

[tex] \bullet [/tex] Slant height (l) of the cone is 6 inches.

To Find:-

Which is closest to the surface area of the cone ?

Solution:-

We know,

Formula of surface area of a cone is πr(r + l) sq. units.

Taking value of π = 3.14

So, Surface area of the cone = 3.14 × 4(4 + 6)

Surface area of the cone = 12.56 × 10

Surface area of the cone = 125.6 sq. inches.

[tex] \because [/tex] 126 sq. inches is closest to 125.6 sq. inches.

So, option (H) 126 sq. in is correct. [Answer]

What is the volume of the prism?

Answers

The formula for the volume of a prism is V=Bh , where B is the base area and h is the height. The base of the prism is a rectangle. The length of the rectangle is 9 cm and the width is 7 cm.

Pls explain how to do this

Answers

Answer:

3 1/12 miles

Step-by-step explanation:

[tex]6\frac{3}{4} -3\frac{2}{3} \\\\=\frac{27}{4} -\frac{11}{3}\\\\ =\frac{81}{12} -\frac{44}{12} \\\\=\frac{37}{12}\\\\=3\frac{1}{12}[/tex]

Make them into mixed fractions and then find the least common denominator (12). solve.

What are the solutions to log6(x^2 + 8) = 1 +log6(x)?

X=-2 and x=-4
X=-1 and x = 8
X= 1 and X=-8
X= 2 and x=4

Answers

Answer: x = 4, x = 2


x² + 8 = 6x

Answer:

D. x=2 and x=4

Step-by-step explanation:

Hope this helps!! Have a great day!! ❤

What is the length of 7.2 ft & 9.6ft

Answers

Answer:

16.8ft !

7.2 + 9.6 = 16.8 ft .

Answer:

12

Step-by-step explanation:

Using Pythagorean Theorem we know that

a² + b² = c²

7.2² + 9.6² = c²

51.84 + 92.16 = 144

Then find the square root of your c and you should get 12

__________________________

Or: 7.2 + 9.6 = 16.8 ft  if that's what you mean

Julius bought F boxes of 24 plastic forks. He already had 39 plastic forks. Now, he has 135 plastic forks. How many boxes of plastic forks did Julius buy in all?

Answers

Julius bought 4 boxes of plastic forks

if the dimensions of the box are 5.4 14.2 and 26.5 what is the volume​

Answers

Answer:

just multiply these decimals ....

multiply... 5.4×14.2×26.5

Can somebody plz help tell me how to find the people who surveyed like where do u find it? Thx!

WILL MARK BRAINLIEST WHOEVER CAN HELP WITH THIS :DDD

Answers

How many people surveyed is just asking you how many people took the survey so count the total amount of tally marks you did

What two number does the cube root of 11 lie between?

Answers

if u know what the sqare root which is 3.32 than it will lie between 2 and 4

Im struggling a lot with these problems can anyone help and show the WORK please?

Answers

Answer:

Step-by-step explanation:

I'll give a couple answers so you get the gist of things.

All you have to do is substitute 1/2 for x and 3/4 for y.

Ex - 30. x × y = 1/2 × 3/4 = 3/8

what is the problem??​

Answers

Answer:

there is none

Step-by-step explanation:

The radius of a sphere measures 2 units What is its surface area?
Surface area
1 square units

Answers

Answer:

A=50.265

Step-by-step explanation:

A

[tex]4\pi {r}^{2} [/tex]

[tex]4\pi {2}^{2} = 50.265482446[/tex]

Answer:

16

Step-by-step explanation:

can anyone explain how this is done.

Answers

Answer:

The answer is C. How many 3/4 -pound molds are in 1/3 pound of sand?

Answer:

The answer is C sorry I didnt answer earlier I had to do something and left brainly open-

hiii please help i’ll give brainliest:)

Answers

Answer:

I think the answer is monarchies(D).

Step-by-step explanation:

Answer:

monarchies

Step-by-step explanation: I found my answer in quiz let so if you want to find the flashcards just look up your question in goo gle to find it have a nice day : )

please solve this math problem very simple for points and if your correct you get brainly

math problem= 3x2x9+3/2-+3=?

Answers

Answer:

58 and 1/2

Step-by-step explanation:

Answer:

52.5

Step-by-step explanation:

54+3/2-3=51+3/2=52.5

given 2x - 9y - 12 = 0, express 5x - 4y + 7 = 0 in terms of x only

Answers

Answer:

[tex]4 \frac{1}{9}x[/tex] + [tex]12\frac{1}{3}[/tex] = 0

Step-by-step explanation:

Based on 2x - 9y - 12 = 0

-9y = 12 - 2x

9y = -12 + 2x

y = [tex]-1\frac{1}{3} + \frac{2}{9} x[/tex]

Therefore...

5x - 4y + 7 = 0

5x - 4([tex]-1\frac{1}{3} + \frac{2}{9} x[/tex]) + 7 = 0

5x + [tex]5\frac{1}{3}[/tex]  - [tex]\frac{8}{9} x[/tex] + 7 = 0

[tex]4 \frac{1}{9}x[/tex] + [tex]12\frac{1}{3}[/tex] = 0

Which point(s) lie on the line whose equation is - 4x + 5y - 12 = 8 Select all that apply. A (5, 0) В (- 2, 2.4) (8, 5) D (10, 12) E (0, 4)

Answers

Answer:

Options B, D and E

Step-by-step explanation:

Given equation is,

-4x + 5y - 12 = 8

-4x + 5y = 20

If a point given in the options lie on the line, point will satisfy the equation.

Option A.

For a point (5, 0),

-4(5) + 5(0) = 20

-20 = 20

False

Therefore, (5, 0) will not lie on the given line.

Option B

For (-2, 2.4)

-4(-2) + 5(2.4) = 20

8 + 12 = 20

20 = 20

True.

Therefore, (-2, 2.4) will lie on the given line

Option C

For (8, 5),

-4(8) + 5(5) = 20

-32 + 25 = 20

-7 = 20

False

Therefore, (8, 5) will not lie on the line.

Option D

For (10, 12)

-4(10) + 5(12) = 20

-40 + 60 = 20

20 = 20

True.

Therefore, (10, 12) will lie on the line.

Option E

For (0, 4)

-4(0) + 5(4) = 20

20 = 20

True.

Therefore, (0, 4) will lie on the line.

Options B, D and E are correct.

19. Find x:
€ (17x-7)*
G
19
HELP W ALL 3 !!

Answers

Answer:

24

(17x-7)

x = 7 + 17

x = 24

h

o

p

e

i

t

w

i

l

l

h

e

l

p

please no link because I can't access it when it's sent.please am asking no link ​

Answers

Answer:

x ≈ 1051.368672

Step-by-step explanation for #3:

[tex]tan(\frac{x}{12}) =24[/tex]          Use tangent function because it relates to the opposite and adjacent sides of the triangle.

[tex]tan^{-1}(tan(\frac{x}{12}))=tan^{-1}(24)[/tex]

[tex]\frac{x}{12} = tan^{-1}(24)[/tex]

[tex]x = 12[tan^{-1}(24)][/tex]

x ≈ 1051.368672

If you have any more questions, feel free to ask and I'll answer them in the comments section under this answer. Please consider marking my answer as Brainliest, because it really helps me out.

Thanks!

F(x)=x^2. What is g(x)?

A. G(x)= x^2–4
B. g(x)= x^2+4
C. g(x)= -x^2-4
D. g(x)= -4x^2

Answers

Answer:

C

Step-by-step explanation:

I'm super sorry if I get this wrong you don't have to choose C I feel like I'm wrong but have a nice day

The admission fee at an amusement park is $1.50 for children and $4 for adults. On a certain day, 235 people entered the park, and the admission fees collected totaled 690.00 dollars. How many children and how many adults were
admitted?

Answers

Y=190
Good luck hope this helps

A map uses the scale 1.5 cm=25 mi. Two cities
are 190 miles apart. How far apart are the cities
on the map?

Answers

Answer: 11.4 cm

Step-by-step explanation:

190/25 = 7.6

7.6 x 1.5 = 11.4

Answer

the two cities are 11.4 cm apart on the map

Please answer correctly

Answers

GDE= 55º

Hope this helps!!

Answer: 55

Explanation: Angle G + Angle D = 180
D + 125 = 180
Angle D = 55

answer for brainilest and 11 points

Answers

Answer:

-16/3

Step-by-step explanation:

I am not sure if you are aware of this but I am not sure if you are aware of the fact

Answer: x=-16/3

Isolate the variable by dividing each side by factors that don't contain the variable.
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