The half-life of carbon-14 is 5,730 years. Suppose a fossil is found with 20 percent as much of its carbon-14 as compared to a living sample. How old is the fossil

Answers

Answer 1

Answer: The sample is 13414 years old.

Step-by-step explanation:

Expression for rate law for first order kinetics is given by:

[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]

where,

k = rate constant  

t = age of sample

a = let initial amount of the reactant= 100

a - x = amount left after decay process= [tex]\frac{20}{100}\times 100=20[/tex]

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

[tex]t_{\frac{1}{2}}=\frac{0.693}{k}[/tex]

[tex]k=\frac{0.693}{5730}=0.00012years^{-1}[/tex]

b) for completion of 20% of reaction

[tex]t=\frac{2.303}{0.00012}\log\frac{100}{20}[/tex]

[tex]t=13414years[/tex]

The sample is 13414 years old.

Answer 2

Answer:    13,307 years

Step-by-step explanation:   i got it right on the quiz/asignment


Related Questions

Identify a set of parallel lines and a set of perpendicular lines in this image

Answers

Answer

It is the first answer.

Step-by-step explanation:

Parallel lines are lines that will never cross each other.

Perpendicular lines are lines that cross each other at 90 degree angles (represented by the box in the corner).

A set of parallel lines and a set of perpendicular lines in this image are; AB║CD, CD ⊥ EF and AB ⊥ EF

How are parallel straight lines related?

Parallel lines have the same slope since the slope is like a measure of steepness and since parallel lines are of the same steepness, thus, are of the same slope.

Since Parallel lines are lines that will never cross each other.

We know that Perpendicular lines are lines that cross each other at 90 degree angles.

The parallel lines are AB and CD, the perpendicular are AB and EF because the first sets are side by side and the second sets cross each other at a certain point.

Therefore the  set of parallel lines and a set of perpendicular lines in this image are; AB║CD, CD ⊥ EF and AB ⊥ EF

Learn more about parallel lines here:

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I suck at math ;-;

Answers

Answer:

50 mph

Step-by-step explanation:

We have the following point

(2,100)

We know that the equation has a y intercept of 0 which means our equation looks like this

y=mx

We know that when x=2 y=100 so

100=2m

m=50

50 mph

Answer:

It’s constant by 50 (1,50) (2,125) and so on

Step-by-step explanation:

25+25=50 75+50=125 and so on

Help me on this plsss

Answers

Answer:

tried my best 2 help

Step-by-step explanation:

2.circumference = pi x diameter

c = pi x (8x2)

c= 50.2654824574

3. when  measuring physical objects,  

4. to find the length around an object such as your waist when buying a top ???? couldnt think of anything else

Which of the following objects show an OBTUSE angle?

Answers

and obtuse angle is greater than 90°
An obtuse angle has a measurement greater than 90 degrees but less than 180 degrees.

Please help asap needed :)

Answers

Answer:

362.35N/m²

Step-by-step explanation:

Pressure = Force/Area

Area = πr²

Area = 3.14(0.75)²

Area = 3.14(0.5625)

Area = 1.76625m²

Force = 640N

Pressure = 640/1.76625

Pressure = 362.35N/m²

There is a bag filled with 6 blue and 5 red marbles.
A marble is taken at random from the bag, the colour is noted and then it is replaced.
Another marble is taken at random.
What is the probability of getting 2 blues?

Answers

Answer:

25 of 121

Step-by-step explanation:

The correct answer is:

25 of 121

hegarty maths man told me so.

Solve for x in the following figure. Choose the appropriate result.

Answers

Answer:

d

Step-by-step explanation:

all of the angles add up to equal 180 so we setup the equation as 45+3x=180

first you subtract each side by 45

135=3x

then you divide each side by 3 and get that

x=45

Answer:

D, 45°

Step-by-step explanation:

at [tex]x=45[/tex]

the resulting angles would be [tex]45, 90, 45[/tex] and these add up to [tex]180[/tex]°

which value of x makes the equation 1.25(4 x-10)=7.5 true?
A. 3.5
B. -1
C. -0.5
D. 4​

Answers

Answer:

4

Step-by-step explanation:

1.25(4x-10)=7.5

First step is to divide the 1.25 on both sides

4x-10 = 6

next step is to get x by itself by adding 10 to both sides

4x = 16

continue getting x by itself by dividing both sides by 4

x = 4.

2.
3. A brand of uncooked spaghetti comes in a box that is a rectangular prism
with a length of 9 inches, a width of 2 inches, and a height of 1 1/2
inches.
What is the surface area of the box? Explain.

Answers

So sorry if I’m wrong but if u divided 11 buy 2 the get 9 divided by 2 witch u should add both of your answers and u get 10 as your answer

Solve the equation

3s-4s=28

Answers

Answer:

-28

Step-by-step explanation:

Answer:

s=[tex]\frac{2}{3}[/tex]

Step-by-step explanation:

least common multiple of 25 and 60

Answers

Answer:

300

Step-by-step explanation:

i multiplied to 300 thats the elast one PLEASE MARK BRAINLIEST

what is a^2+15^2=17^2

I can't figure out what A is... HELP PLSSSSSSSSSSSSSSSSSSSSS
:3

Answers

Answer:

Step-by-step explanation:

Answer:

im bad at math sawy

Step-by-step explanation:

Can someone help me with this please???...

Answers

Answer:

2×2×2×2× 5

Step-by-step explanation:

use the tree method it helps

Answer:

hey mate this is your answer..

multi-step equation
solve:
2p-3p-p=9-15-6

Answers

Answer:

p=-6

Step-by-step explanation:

2p-3p-p=9-15-6

or, -2p= -12

or, p= -12/-2

or, p= -6

interest earned:? principal: 250$ interest rate: 4% time: 2 years

Answers

First begin with the interest formula.

Interest = Principal x Rate x Time

The $250 is the principal is the amount of money invested.

The rate is 4% which translates to the decimal .04.

The time is 5 years.

So we have I = (250)(.04)(2).

Multiplying, (25)(.04) is 10 and we have 10(2) which is 20.

This means that the interest earned in 2 years is $20.

Oliver is playing a math game. He chose three cards. The value of each card is shown.
First card -11. Second card 4. Third card -7 What is the sum of Oliver's three cards?

Answers

Answer:

1234567dgidchtdcjtdjutchitcbjtxvutx

Find the LCD. 9, 12 The LCD is



please help and quick!!

Answers

Answer:

There is no such thing as LCD but I think you are trying to find LCM. LCM is least common multiple which is 36 because 9*4=36 and 12*3 also equals 36

Step-by-step explanation:

Answer:

36

Step-by-step explanation:

Find prime factors of the given numbers

9 = 3*312 = 2*2*3

Find the LCD

LCD(9, 12) = 3*3*2*2 = 36

Can someone help me with this please?

Answers

4 times bbbbbbbbbbbbbbbbbbb

Write equation of a line parallel or to a y=2x+3 that passes the ordered pair (3,6)

Answers

Answer:

y = 2x

Explanation:

To write the equation of a line u use the formula y = mx + b, where

y = y coordinate

m = slope

x = x coordinate

b = y intercept

One thing about parallel lines is that they always have the same slope. If you want to find a line parallel to y = 2x + 3, then the parallel line will also have a slope of 2.

So far, then, the equation would look like this: y = 2x + b

To find the y-intercept, we substitute in the values from (3,6) into the equation because the line passes through that point. So:

y = 2x + b

(6) = 2(3) + b

6 = 6 + b

6 - 6 = b

b = 0

Since the y-intercept is 0 (so the line passes through the origin), it doesn't need to be written on to the end of the equation.

y = 2x + 0 is just

y = 2x

That's your final equation! hope this helps!

Write the equation of the line in slope intercept form that has a slope of -1/5 and contains (-5,-3)

Answers

Answer:

y = [tex]-\frac{1}{5}x[/tex] - 4

Step-by-step explanation:

As we know the point slope form of an equation is as follows -

y - y₁ = m ( x - x₁ )

As we have slope , m = [tex]-\frac{1}{5}[/tex]

And point (x₁ , y₁ ) = ( -5, -3)

⇒ y - ( -3) = [tex]-\frac{1}{5}[/tex] ( x - (-5) )

⇒ y + 3 = [tex]-\frac{1}{5}[/tex] ( x + 5 )

⇒ y + 3 = [tex]-\frac{1}{5}[/tex] x - 1

⇒ y =  [tex]-\frac{1}{5}[/tex] x - 1 - 3

⇒ y =  [tex]-\frac{1}{5}[/tex] x - 4

So, the equation becomes

y = [tex]-\frac{1}{5}x[/tex] - 4

What is the domain of the relation

Answers

Answer:

0≤x≤3

Step-by-step explanation:

The domain is just all the possible values of x

we can see that the line goes through the x values 0 through 3

which means that

0≤x≤3

It's ≤ because it's a close circle

The sum of two numbers is 18 and their difference is 4 what are the two numbers?

Answers

Answer:

7 and 11

Step-by-step explanation:

Let the two numbers be x and y

x+y = 18

x-y = 4

Add the two equations together to eliminate y

x+y = 18

x-y = 4

----------------

2x +0y = 22

Divide each side by 2

2x/2 = 22/2

x = 11

Solve for y

x+y = 18

11+y =18

Subtract 11 from each side

11+y-11 =18-11

y = 7

The two numbers are 7 and 11

2 + 6m + 7 = 57
pls show your work pls.
i need a full answer

Answers

Answer:

m=8

hope this helps

have a good day :)

Step-by-step explanation:

2 + 6m +7=57

9+6m=57 add like terms

6m=48 subtract 9 from each side

m=8 divide by 6 on each side

Answer:

M=8

Step-by-step explanation:

First your going to subtract 2 from 7 and thats 5.

then your going to do:

6m+5=57

Then subtract 5 from 57 and thats 52

and divide 52 from 6 and thats 8.

please help again :,)) is it one solution, all solutions, or one
please show your work.

Answers

Answer:

Infinite many solutions

Step-by-step explanation:

If you graph it there is only 1 line

Help please help help help:)

Answers

Answer:

1/8 of a pound

Step-by-step explanation:

(3/4) ÷ 6 = .125 = 1/8

Andrew collects coins. He collected a total of 275 coins. If 84% of the coins he collected were foreign, how many other coins did he collect? Andrew collected coins that were not foreign​

Answers

Answer:

44

Step-by-step explanation:

1. Find out how many coins were foreign

x.           84

------ = ---------

275.      100

2. Subtract 231 (Foreign coins) by 275 (Total coins)

3. The answer is 44

The percentage is calculated by dividing the required value by the total value and multiplying by 100.

The number of foreign coins.

84% of 275 = 231

The number of foreign coins is 231.

What is a percentage?

The percentage is calculated by dividing the required value by the total value and multiplying by 100.

Example:

Required percentage value = a

total value = b

Percentage = a/b x 100

Example:

50% = 50/100 = 1/2

25% = 25/100 = 1/4

20% = 20/100 = 1/5

10% = 10/100 = 1/10

We have,

Total number of coins = 275

Percentage of foreign coins = 84%

The number of foreign coins.

= 84% of 275

= 84/100 x 275

= 231

Thus,

The number of foreign coins is 231.

Learn more about percentages here:

https://brainly.com/question/11403063

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calculate the total amount of milk in three cartons if each carton contains 236 ml of milk

Answers

236 x 3 = 708ml of milk

1.2.1
Question Help
An airplane on autopilot took 8 hours to travel 5,616 kilometers. What is the unit rate for kilometers per hour?
The unit rate is kilometer(s) per hour.
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Answers

702km per hour is the correct answer

2x = 3y + 2
y = -x +6

Answers

Answer:

x=4 and y=2

Step-by-step explanation:

2x=3(-x+6) +2

2x= -3x+18 +2

2x= -3x+20

5x=20

x=4

y=-(4) +6

y=2

Wanda is making a border around her garden. She buys 9 bricks for her border. The bricks
weigh 27 kilograms in all.
How much does each brick weight

Answers

Answer:

3 kilograms...........

Answer:

27 ÷ 9 = 3

well , yeah , am i right ?

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