answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Iteru [2.4K]
2 years ago
11

An old campfire is uncovered during an archaeological dig. Its charcoal is found to contain less than 1/1000 the normal amount o

f ^{14}\text{C} ​14 ​​ C. Estimate the minimum age of the charcoal, noting that
Mathematics
1 answer:
Lubov Fominskaja [6]2 years ago
5 0

An old campfire is uncovered during an archaeological dig. Its charcoal is found to contain less than 1/1000 the normal amount of ^{14}\text{C} ​. Estimate the minimum age of the charcoal, noting that  2^{10} = 1024

Answer:

57300 years

Step-by-step explanation:

Using the relation of an half-life time in relation to fraction which can be  expressed as:

\dfrac{N}{N_o} = (\dfrac{1}{2})^{\frac{t}{t_{1/2}}

here;

N represents the present atom

N_o represents the  initial atom

t represents the time

t_{1/2} represents the half - life

Given that:

Its charcoal is found to contain less than 1/1000 the normal amount of ^{14}\text{C} ​.

Then ;

\dfrac{N}{N_o} = \dfrac{1}{1000}

However; we are to  estimate the minimum age of the charcoal, noting that  2^{10} = 1024

so noting that 2^{10} = 1024, then:

\dfrac{1}{1000}> \dfrac{1}{1024}

\dfrac{1}{1000}> \dfrac{1}{2^{10}}

\dfrac{1}{1000}> (\dfrac{1}{2})^{10}

If

\dfrac{N}{N_o} = \dfrac{1}{1000}

Then

\dfrac{N}{N_o} > (\dfrac{1}{2})^{10}

Therefore, the estimate of the minimum time needed is 10 half-life time.

For ^{14}\text{C} , the normal half-life time = 5730 years

As such , the estimate of the minimum age of the charcoal =  5730 years × 10

= 57300 years

You might be interested in
VIE.IN
ch4aika [34]

Answer:

2.88 pounds or 288 ounces

Step-by-step explanation:

you need 12oz

and 24 bags

multiply those    

5 0
2 years ago
If x% of four-digit numbers have a repeated digit (the repeated digits do not need to be adjacent), then what is x? Express your
joja [24]

Answer

It is a 4 digit number but 1 digit (exactly one digit) is repeated just once.

So 3 digits out of 10 have to be chosen.

There are 10C3 = 120 ways to do this.

say the digits chose are 5,6 and 9, they can be in any order and there are 3! possible orders =6 orders.

So so far that is 120*6=720 ways to get a 3 digit number where the digits are all different.

But we want a 4 digit number.

One digit has to be repeated there are 3 possibilities so that is 720*3 = 2160 posibilities.

But there are 4 postions that extra number can be put in. So that is 2160*4=8640 numbers

But I have double counted because 1434 is the same if I swap the 4s around so I have to halve this answer

8640/2 = 4320

So the number of favourable outcomes is 4320.

Altogether there are 10*10*10*10 = 10000 4 digit numbers (if they are allowed to start with 0)

so the prob of getting just one digit repeated once is 4320/10000 = 0.4320 = 43.2%

Do you understand now?

You will need to write your query on this thread but also send me a private message with the address of this thread attached. Otherwise I will not see it.

If you do have a query try to ask a specific question.

Anyway I hope that you understand

8 0
2 years ago
Consider the following problem: A farmer with 950 ft of fencing wants to enclose a rectangular area and then divide it into four
Alina [70]

Answer:

Step-by-step explanation:

(a)

Suppose we came up with an ideology whereby we pick a value for the length including the length dividing the inside into 4 parts(5 parallel sides), then we can get the value for breath by using the following process.

Let assume the length of the rectangle is 50;

Then, the breath can be calculated as follows:

= 50 × 5 = 250   ( since the breath is divided into 5 parallel sides)

The fencing is said to be 950 ft

So, 950 - 250 = 700

Then divided by 2, we get:

= 700/2

= 350

So for the first diagram; the length = 50 and the breath = 350

The area = 50 × 350 = 17500 ft²

Now, let's go up a little bit.

If the length increase to 100;

Then 100 × 5 = 500

⇒ 950 - 500 = 450

⇒ 450/2 = 225

The area = 225 × 100 = 22500 ft²

Suppose the length increases to 150

Then 150 × 5 = 750

⇒ 950 - 750 = 200

⇒ 200/2 = 100

The area = 150 × 100 = 15000 ft²

The diagrams for each of the outline above can be seen in the image attached below.

(b) The diagram illustrating the general solution can be seen in the second image provided below.

(c) The expression for  the total area A in terms of both x and y is:

Area A = x×y

(d) Recall that:

The fencing is said to be 950 ft.

And the length is divided inside into 5 parallel sides;

Then:

5x + 2y = 950  (from the illustration in the second image below)

2y  = 950 - 5x

y = \dfrac{950}{2} - \dfrac{5}{2}x

y = 475- \dfrac{5}{2}x

(e)

From (c); replace the value of y in (d) into (c)

Then:

Area A = x×y

f(x)= x\times ( 475 -\dfrac{5}{2}x)

Open brackets

f(x)= ( 475 x-\dfrac{5}{2}x^2)

(f)

By differentiating what we have in (e)

f(x)= ( 475 x-\dfrac{5}{2}x^2)

f'(x)= ( 475 (1)-\dfrac{5}{2}(2x))

f'(x)= 475 -5x

\implies  475 = 5x

x = 475/5

x = 95

From (d):

y = 475- \dfrac{5}{2}x

y = 475- \dfrac{5}{2}(95)

y =237.5

∴

Area A = x × y

Area A = 95 × 237.5

Area A = 22562.5 ft²

5 0
2 years ago
In which diagram are angles 1 and 2 vertical angles?
Solnce55 [7]

<u>Answer</u>

First diagram shows  1 and 2 vertical angles

<u>Explanation</u>

From the all four diagrams,we get the diagram first shows the vertically opposite angles.  

angle 1 and angle 2 are vertically opposite angles

vertically opposite angles are equal in measurements. when two lines are intersect each other form four angles, out of this four angles two pairs of vertically opposite  angles are there.

All other figures  angle 1 and 2 shows adjacent angles.

6 0
2 years ago
Read 2 more answers
A basketball player has made 70​% of his foul shots during the season. Assuming the shots are​ independent, find the probability
bija089 [108]

Answer:

a) 0.07203

b) 0.0189

c) 0.973

Step-by-step explanation:

Probability of making one shot, for the player = 70% = 0.70

Probability of NOT making a shot = 1 - 0.70 = 0.30

Assuming that the shots are​ independent

a) Misses for the first time on his fifth attempt ​

For him to miss on his for the first time on his fifth attempt, he has to make the first four shots

The required probability = (0.7)⁴(0.3) = 0.07203

b) Makes his first basket on his fourth shot

For him to make his first basket on the fourth shot, he has to miss the first three shots.

Required probability = (0.3)³(0.7) = 0.0189

​c) Makes his first basket on one of his first 3 shots

This is a sum of probabilities; that is, he could make the first basket on the first shot, or miss on the first shot and make the second shot or miss on the first two shots and make the basket on the third shot.

Required probability

= (0.70) + (0.3×0.7) + (0.3×0.3×0.7)

= 0.70 + 0.21 + 0.063 = 0.973

Hope this Helps!!!

3 0
2 years ago
Other questions:
  • In isosceles triangle the length of the base is twice shorter than the length of a leg. The perimeter of this triangle is 50cm.
    6·1 answer
  • a) The table below shows the populations of several states (in millions) and the number of motor vehicle deaths in each. Complet
    7·1 answer
  • Della bought a tree seedling that was 2 1/4 feet tall. During the first year, it grew 1 1/6 Feet. After two years, it was 5 feet
    10·1 answer
  • what is the equation of the line of best fit for the following data round the slope and y intercept of the line to three decimal
    10·2 answers
  • Given f(x) and g(x) = f(x) + k, look at the graph below and determine the value of k. k = ______ Graph of two lines. f of x equa
    10·1 answer
  • 10+4 to the 3 power times 2 to the negative 2
    5·1 answer
  • ? QUESTION
    13·1 answer
  • David is 22 years old. He buys 100/300/50 liability insurance, collision insurance with a $100 deductible, and comprehensive ins
    6·1 answer
  • A surf instructor has an initial fee of $12 and charges $8
    13·2 answers
  • A 1,200-kg automobile is traveling at a velocity of 100 m/s. Is its energy potential or kinetic? How much energy does it possess
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!