The half-life of cobalt-60 is 5.20 yr. how many milligrams of a 2.000-mg sample remains after 6.55 years?

Answers

Answer 1

Answer:

0.835 mg of a 2.000-mg sample remains after 6.55 years.

Step-by-step explanation:

We are given that The half-life of cobalt-60 is 5.20 yr.

Formula of half life : [tex]N(t) = N(0)e^{\frac{-0.693t}{t\frac{1}{2}}}[/tex]

Where N(0) = Initial amount

N(t) = Quantity remaining after time

t = time

[tex]\frac{t}{2} =\text{half life}[/tex]

So, N(0) = Initial amount = 2 mg

t = time = 6.55 years

[tex]\frac{t}{2} =\text{half life} = 5.20 yr [/tex]

Substitute the values in the formula

Therefore,

[tex]N(t) = 2 e^{\frac{-0.693 \times 6.55}{5.20}}[/tex]

[tex]N(t) =0.835[/tex]

Hence 0.835 mg of a 2.000-mg sample remains after 6.55 years.


Related Questions

Help me please!! I wanna make my mother proud>3

Find the product.

4(−12)(−3)
A) −144
B) −96
C) 144
D) 72

Answers

I believe it's C.

Hope this helps!
a) learn to use your calculator

b) recognize that the even number of minus signs will mean the product is positive, and that 4*3 = 12, so this becomes 12² = 144 (math facts you have memorized).

The appropriate choice is ...
   C) 144

Which ordered pair is the best estimate for the solution of the system of equations? y=−12x+4y=12x−3 (7, 1) (7, 0) (7, 0.5) (7.5, 0.5)

Answers

A quick way of doing this is to use a graphing calculator and find the point in which both graphs intersect. Another way of doing this is to substitute. Substitute the x’s and y’s of each equation in for each ordered pair and look for the one that is true. Though what’s confusing me is that, the solution is (0.3,0.5).
ANSWER

[tex](7,0.5)[/tex]

EXPLANATION

We want to solve the system;

[tex]y = - \frac{1}{2} x + 4...(1)[/tex]
and

[tex]y = \frac{1}{2} x - 3...(2)[/tex]

Add equations (1) and (2) to get,

[tex]y + y = 4 + - 3[/tex]

This implies that,

[tex]2y = 1[/tex]

[tex]y = \frac{1}{2} [/tex]

or

[tex]y = 0.5[/tex]

We put y=½ into equation (2) to get,

[tex] \frac{1}{2} = \frac{1}{2} x - 3[/tex]
Multiply through by 2 to get,

[tex]1 = x - 6[/tex]
This implies that,

[tex]x = 1 + 6 = 7[/tex]

Therefore the best estimate for the system of equations is
[tex]
(7,0.5)[/tex]
The correct answer is C

Given: triangle ABC, AB = BC Perimeter of ΔABC = 50 Perimeter of ΔABD = 40 Find: BD

Answers

The answer is 15. You can use a equation 2x+2y=50 for ABC  and so then x+y=25. x+y+h=40(ABD), so h is 15 units.

The measure of angle ABC and BDC is 80° and 90° respectively.

What is the triangle?

In geometry, a triangle is a closed, two-dimensional shape with three straight sides. A triangle is also a polygon.

Given the ΔABC in which AB ≅ BC, m∠ABD = 40° and BD is the median of ΔABC.

We have to find the measure of angle ∠ABC and ∠BDC.

As the median of the isosceles triangle split the angle at the vertex into two equal parts i.e ∠ABC is twice the angle ∠ABD.

[tex]\rm \angle ABC=2\angle ABD\\\\\angle ABC=2 \times 40\\\\\angle ABC=80[/tex]

Also, the median of an isosceles triangle is perpendicular to the opposite side i.e to the base. Here, BD is perpendicular to AC.

∠BDC=90°

Therefore, the measure of angle ABC and BDC is 80° and 90° respectively.

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Mr. Sanchez bought 2 magazine for 9.95 each and 1 book for 14.95 if the sales tax is 6% what is the total cost of Mr. Sanchez purchases

Answers

rst you have to find the price of everything together

2 magazines for 9.95 each and a book for 14.95

9.95 + 9.95 + 14.95 = 34.85

Next you convert the percent to a decimal

6% = 0.06

Now you put a one in the ones place

1.06

Multiply this by the cost of everything

34.85 * 1.06 = 36.94

The answer is $36.94

Hope this helps!

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David is making a mosaic using 63 glass tiles 105 ceramic tiles and 84 marble tiles he wants to put the same number of each type of tile and Rose what is the maximum number of times you can have in each row

Answers

The largest number that divides 63, 84, and 105 evenly is 21.

David can put 21 of each kind of tile in a row.

_____
These numbers are 3*21, 4*21, and 5*21, respectively.

PLEASE HELP!

1. If you cut out all the nets carefully, fold along the inside lines and tape edges together to form 5 figures. Describe the figures formed. What shapes are they? Are any the same?

2. What does the fact that the figures fit together to make the prism tell you about their combined volume?

Answers

Well, first of all, A was the only one visibly different as in shape.
The first picture is A. The rest should be in order like this: A, B, E, D,C.
Yes I know I did a crummy job at taping but hey, I tried.

Brad has 3 pairs of pants, 7 tee shirts, and 2 pairs of sneakers. How many different outfit combinations can he wear

Answers

HE CAN WEAR 42 DIFFERENT COMBOS

Answer:

42

Step-by-step explanation:


A snow storm left 1.25 feet of snow on the ground overnight. At noon today, the temperature will be above freezing and the snow will melt. If the melting snow is modeled by the equation y = -1 3 x + 1.25, how long will it take for the snow to melt away?

Answers

y = -13x + 1.25
0 = -13x + 1.25
-1.25 = -13x
3.75 = x

then,

3.75 hours  to 3 hours 45 minutes 

What is the ratio (fraction) of minivans to all vehicles on the forecourt?
A)1/120
B)1/20
C)1/6
D)1/4

Answers

there is a total of 120 and 20 minivans so
20/120
1/6
I hope this helps

do u do keystone

? im just wondering i do

Q # 8 please solve the question

Answers

Let the two numbers be x and y

Their sum is 20, so we can write
x + y = 20

Their difference is 14, so we can write:
x- y = 14


Adding the two equations, we get:

2x = 34
x = 17

Using the value of x, in first equation, we get:

17 + y = 20
so,
y = 3

Thus the two numbers are 17 and 3.

So, option a is the correct answer
For this case we have the following system of equations:
 x + y = 20
 x-y = 14
 Where,
 x: real number
 y: real number
 Solving the system we have:
 x = 17
 y = 3
 Therefore, the numbers are:
 17 and 3
 Answer:
 
17 and 3
 
option 1

Ezra is training for a track race. He starts by sprinting 100 yards. He gradually increases his distance, adding 5 yards a day for 21 days.

Answers

On the 21st day, he sprints 205 yards.

Is that what you meant for the problem

or do u want to know how many yards he sprinted total for the 21 days
If it is,
he sprinted a total of 3390 yards

On Apex the correct one is 200 yards.

given that an arithmetic sequence can be expressed as a linear function in the form f(x)=mx+b, write a linear function to describe the sequence {10,15,20,25,30,35...}

Answers

For this case we have:
 m = (y2-y1) / (x2-x1)
 m = (15-10) / (2-1)
 m = 5/1
 m = 5
 Then,
 y-yo = m (x-xo)
 where,
 (xo, yo) = (1, 10)
 Substituting:
 y-10 = 5 (x-1)
 y = 5x -5 + 10
 y = 5x + 5
 Answer:
 
a linear function to describe the sequence is:
 
y = 5x + 5

Answer:

a linear function to describe the sequence is:

y = 5x + 5

Step-by-step explanation: ik ur on usa te$t prep

Nan and sato are designing a coffee table would you sing 4 inches tile Nan uses 30 tiles and sato uses half as many many total tiles did they use

Answers

the correct question in the attached figure

it is assumed that the tile is square
area of the square=b²
b is the length side of a square
b=4 in
area of the tile=4²----> 16 in²

Part 1)  How many total tiles did they use?
Nao uses 30 tiles
and 
Sato uses (1/2)*30=15
so
Nao and Sato uses----> 30+15----> 45 tiles

the answer Part 1) is
45 tiles

Part 2) If the area of the table is 36 inches by 26 inches, will they have enough tiles for the table?

find the area of the table
area of the table=36*26----> 936 in²

area of one tile=4*4----> 16 in²

if 1 tile------------------> 16 in²
x tiles-------------> 936 in²
x=936/16----> x=58.5 tiles

58.5 > 45
so
there are not enough tiles for the table

the answer part 2) is
there are not enough tiles for the table

Part 3)  If not, how many more will they need?

tiles required=58.5-45------> 13.5-----> 14 tiles

the answer part 3) is
14 tiles

Nan and Sato together used 45 tiles for their coffee table design.

The student's question involves calculating the total number of tiles used by two individuals, Nan and Sato, who are designing a coffee table. Nan uses 30 tiles, and Sato uses half as many tiles as Nan does. To find out how many tiles Sato uses, we divide Nan's number of tiles by 2.

So, Sato uses 15 tiles because half of 30 is 15. To find out the total number of tiles used, we add Nan's tile count to Sato's tile count:

30 tiles (Nan) + 15 tiles (Sato) = 45 tiles in total.

Therefore, to determine the total number of tiles used, Nan's 30 tiles are added to Sato's 15 tiles (half of Nan's), resulting in a total of 45 tiles used for the coffee table design.

If the numerator of a fraction is increased by 3, the fraction becomes 3/4. If the denominator is decreased by 7, the fraction becomes 1. Determine the original fraction. Which of the following equations represents "If the numerator of a fraction is increased by 3, the fraction becomes 3/4"?

Answers

For this case, the original fraction is:
 x / y
 Where,
 x = numerator
 y = denominator:
 If the numerator of a fraction is increased by 3, the fraction becomes 3/4:
 (x + 3) / y = 3/4
 If the denominator is decreased by 7, the fraction becomes 1:
 x / (y-7) = 1
 Solving the system of equations we have:
 x = 9
 y = 16
 The original fraction is:
 9/16
 Answer:
 
the original fraction is:
 
9/16
 "If the numerator of a fraction is increased by 3, the fraction becomes 3/4" is:
 (x + 3) / y = 3/4

find 1/9 as many as 3 divided by 5

Answers

Final answer:

To find 1/9 as many as 3/5, you multiply 3/5 by 1/9 to get 3/45, which simplifies to 1/15.

Explanation:

To solve the student's question, we need to find what is 1/9 as many as 3/5. This involves multiplying the fraction 3/5 by the fraction 1/9. Here is the step-by-step calculation:

Multiply the numerator of the first fraction (3) by the numerator of the second fraction (1) to get the numerator of the answer.Multiply the denominator of the first fraction (5) by the denominator of the second fraction (9) to get the denominator of the answer.Combine these to get the answer in fractional form.

The calculation will look like this: (3/5) × (1/9) = 3/45 = 1/15.

Thus, 1/9 as many as 3/5 is 1/15.

What is the distance d across the lake?

Answers

Answer-

The distance d across the lake is 90ft.

Solution-

In the picture,

ΔABC ≈ ΔCDE

Because,

∠ACB = ∠DCE (∵ vertical opposite angles)∠B = ∠D = 90°∠ACB = ∠CED (∵ as other two angles are same and sum of those two angles when subtracted from 180° will result the same)

So, from similarity properties

[tex]\Rightarrow \dfrac{AB}{DE}=\dfrac{BC}{DC}[/tex]

[tex]\Rightarrow \dfrac{120}{20}=\dfrac{d}{15}[/tex]

[tex]\Rightarrow d=\dfrac{120\times 15}{20}=90[/tex]

hey can you please help me posted picture of question

Answers

The correct answer is the Option C, which is:

 C. G(x)=(x-2)^3

 The explanation is shown below:

 1. You have the the red graph has the equation F(x)=x^3
 2. If you shifted two units to the right, you must add -2 to the function x^3, as below:

 G(x)=(x-2)^3

 3. If you want to verify this is correct, you need to give values to the variable x and plot each point.
 4. You will see that the correct answer is the option mentioned above.

Find the length of JK and the measure of M

Answers

Comment
You have two different situations, but both of them are solved the same way.

Step One
Solve for the 2 equal sides.
21x - 9 = 3x + 27   Add 9 to both sides.
21x = 3x + 27 + 9
21x = 3x + 36       Subtract 3x from both sides.
21x - 3x = 36
18x = 36               Divide by 18
x = 36/18
x = 2

That's not quite the answer

Step Two
Find JK
JK = 21x - 9
JK = 21*2 - 9
JK = 42 - 9
JK = 33  <<<<<<< Answer

Step Three 
Solve for y
5y + 11 = 12y - 10 Subtract 5y from both sides.
11 = 12y - 5y  - 10
11 = 7y - 10          Add 10 to both sides.
11 + 10 = 7y     
21 = 7y                 Divide by 7
21/7 = y
3 = y

Step Four
Solve for M
M = 12y - 10
M = 12*3 - 10
M = 36 - 10
M = 26  <<<<< Answer
JK = 33
M = 74

Hope this Helped!

;D
Brainliest??

What is the angular velocity of a 6–foot pendulum that takes 3 seconds to complete an arc of 14.13 feet? Use 3.14 for π.

Answers

The angular velocity is the linear speed divided by the radius.
  ω = d/(t*r) = (14.13 ft)/((3 s)*(6 ft))
  ω = 0.785 radians/second
There are 180/π degrees per radian, so the angular velocity can also be written as ...
  ω = 45 degrees/second

What are the zeros of the function?

F (X) = x^3 - x^2 - 6x

A) -1, 0, and 3

B) -3, 0, and 1

C) -3, 0, and 2

D) -2, 0, and 3

Answers

Try this explanation:
if to re-write the function f(x)=x(x²-x-6), then to make up the equation x(x²-x-6)=0, it is possible to find the zeros requred:
x(x-3)(x+2)=0, x=0;x=-2;x=3.

answer: D -2;0;3
The answer is B. Just finished the test. 

Cards are dealt, one at a time, from a standard 52-card deck. a if the first 2 cards are both spades, what is the probability that the next 3 cards are also spades?

Answers

So we already drew two cards and both of them are spades. So that means there are 50 cards and 11 spades left.

Then third card being spades would be 11 / 50

Now there are 10 spades and 49 cards left.
So the probability for fourth card would be 10 / 49

Fifth card would be 9 / 48.

So the probability of next three cards being spades would be
[tex]\dfrac{11}{50}\cdot\dfrac{10}{49}\cdot\dfrac9{48}=\dfrac{33}{3920}\approx\boxed{0.00842}[/tex]

Hope this helps.

Quadrilateral has angles 45 degrees, 150 degrees, 65 degrees, and N degrees

Answers

n=100
other angles=260
all interior angles of a quadrilateral add up to 360

Which answer shows a correct order to solve this story problem? Maurine had to pay $2.52 tax on her purchases. She bought 3 books for $12.99 each, 2 pens for $0.69 each, and a magazine for $2.99. How much did Maureen spend? A. Step 1: Add the price of a book and a pen. Step 2: Multiply by 3 and then by 2. Step 3: Add $2.99 to that result. Step 4: Add the tax to the total of the purchases. B. Step 1: Calculate the total price of the 2 pens. Step 2: Add $2.99 to that total. Step 3: Calculate the total price of the 3 books. Step 4: Add the tax to the price of the 3 books C. Step 1: Calculate the total price of the 3 books. Step 2: Calculate the total price of the 2 pens. Step 3: Add $2.99 to the total of the cost of the books and pens. Step 4: Add the tax to the total of the purchases. D. Step 1: Add $2.99 to the amount of the tax. Step 2: Calculate the total price of the 2 pens. Step 3: Calculate the total price of the 3 books. Step 4: Add the prices of the pens to the price of the books.

Answers

The usual choice would be
  C. Step 1: find the price of the books; Step 2: find the price of the pens; Step 3: add the prices of the books, pens, and magazine; Step 4: add the tax.


_____
You can, of course, find and add the constituent prices in any order. Generally, you need to know that subtotal in order to figure the tax, which is then added to that subtotal. If you've ever done any shopping at a store where bills are added manually, or if you pay attention to any cash register receipt, you know this is the process.

A display that shows how the values in a data set are distributed

Answers

Answer: Line Plot

Step-by-step explanation: A line plot is a display that shows how the values in a data set are distributed.

Answer: histogram

Step-by-step explanation:

Find a unit vector that is perpendicular to the vector 5, −4

Answers


[tex]( \frac{4}{ \sqrt{41} } , \frac{5}{ \sqrt{41} } )[/tex]

Regina's mom bought her some bracelets. There were a total of 85 bracelets in 5 packages.

Which of the following equations would describe n, the number of bracelets that were in one package?

A. n + 5 = 85

B. n ÷ 5 = 85

C. n - 5 = 85

D. n × 5 = 85

Answers

The answer your looking for is B

At a college, 4/5 of the students take an English class. Of these students, 5/6 Composition. Which fraction of the students at the college take Composition?

Answers

If I’m doing it correctly it’s 2/3 but I haven’t done it in a while
Final answer:

The fraction of students who take Composition at the college is 2/3.

Explanation:

To find the fraction of students who take the Composition class, we need to multiply the fraction of students who take an English class (4/5) by the fraction of English students who take the Composition class (5/6).

Multiplying these fractions, we get (4/5) * (5/6) = 20/30 = 2/3.

Therefore, 2/3 of the students at the college take Composition.

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An electrolyte solution has an average current density of 111 ampere per square decimeter \left( \dfrac{\text{A}}{\text{dm}^2}\right)( dm 2 A ​ )left parenthesis, start fraction, A, divided by, d, m, start superscript, 2, end superscript, end fraction, right parenthesis. What is the current density of the solution in \dfrac{\text{A}}{\text{m}^2} m 2 A ​ start fraction, A, divided by, m, start superscript, 2, end superscript, end fraction?

Answers

Average current density of the solution = 1 ampere per square decimeter

We have to find the average current density of the solution in ampere per square meter.

1 decimeter = [tex] \frac{1}{10} [/tex] meter
Squaring both sides we get

1 decimeter square = [tex] \frac{1}{100} [/tex] meter square

Current density = [tex]1 \frac{A}{dm^{2} } =1 \frac{A}{ \frac{1}{100} m^{2} } =100Am^{-2} [/tex]

Thus, the density of electrolyte solution is 100 ampere per square meter

Answer:

Answer is 100

Step-by-step explanation:

Find (tan A+B) if A and B are in quadrant 2 with tan A=(1/3) and sin B=(20/29)

Answers

Final answer:

The value of [tex]\( \tan(A + B) \)[/tex] in quadrant 2, where [tex]\( \tan A = \frac{1}{3} \)[/tex] and [tex]\( \sin B = \frac{20}{29} \)[/tex], is [tex]\( \frac{11}{57} \)[/tex].

Explanation:

To find [tex]\( \tan(A + B) \)[/tex], we can use the formula [tex]\( \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \)[/tex]. Given that \[tex]( \tan A = \frac{1}{3} \)[/tex] and [tex]\( \sin B = \frac{20}{29} \)[/tex], we can determine [tex]\( \cos B \)[/tex] using the fact that [tex]\( \sin^2 B + \cos^2 B = 1 \)[/tex]. Therefore, [tex]\( \cos B = \sqrt{1 - \sin^2 B} = \frac{21}{29} \)[/tex].

Now, substitute the values into the formula for [tex]\( \tan(A + B) \)[/tex]:

[tex]\[ \tan(A + B) = \frac{\tan A + \tan B}{1 - \tan A \tan B} \][/tex]

[tex]\[ = \frac{\frac{1}{3} + \frac{20}{29}}{1 - \frac{1}{3} \cdot \frac{20}{29}} \][/tex]

[tex]\[ = \frac{\frac{29 + 60}{87}}{\frac{87 - 20}{87}} \][/tex]

[tex]\[ = \frac{\frac{89}{87}}{\frac{67}{87}} \][/tex]

[tex]\[ = \frac{89}{67} \][/tex]

Therefore, [tex]\( \tan(A + B) = \frac{11}{57} \)[/tex] in quadrant 2.

Final answer:

To find (tan A+B) when A and B are in quadrant 2, find the components of A and B along the x- and y-axes using A = 34.0 m, θA = 63.0°. Calculate Ax = A cos θA and Ay = A sin θA. Then use the formula tan(A + B) = (tan A + tan B) / (1 - tan A tan B) to find the sum of the tangents.

Explanation:

First, we find the components of A and B along the x- and y-axes. From the problem, we know that A = B = 34.0 m, and θB = 63.0°. We find the x-components by using Ax = A cos θ, which gives Ax = 34.0 cos 63.0° = -15.23 m.

Similarly, we find the y-components by using Ay = A sin θ, which gives Ay = 34.0 sin 63.0° = 29.88 m.

Now, we can find the sum of the tangents of A and B using the formula tan(A + B) = (tan A + tan B) / (1 - tan A tan B). Substituting the given values, we have tan(A + B) = (1/3 + Ay/Ax) / (1 - (1/3)(Ay/Ax)).

Two graphs are shown below:

graph A shows scatter points 1, 1 and 2, 2 and 3, 3 and 4, 4 and 5, 5graph A shows scatter points 1, 4 and 2, 4 and 3, 4 and 4, 4 and 5, 4

Which scatter plot shows a positive correlation between x and y?

Only graph A
Only graph B
Both graph A and graph B
Neither graph A nor graph B

Answers

The answer would be graph A because positive correlation is when the X and Y axis advance together. 

The correct answer is graph A

Other Questions
Write the sum using summation notation, assuming the suggested pattern continues.-8 - 3 + 2 + 7 + ... + 67 Match the following:1.Cost2.Benefit 3.Interest 4.Money5.Complements6.Substitutes7.Regulations8.National Debttotal amount that the government owesrules that govern behaviorsomething given up as the result of a decisiongoods that go together, like peanut butter and jellysomething gained from a decisioncurrency, coins, and checking account depositsgoods that can replace each other, like mittens and glovespriceof money saved or borrowed According to erikson, achieving a sense of identity is the special task of the: Naomi is an achievement-oriented, efficient project manager who generally attributes her success to her own actions but tends to blame situational factors when it comes to her failures. this tendency of hers exemplifies a(n) _____. Give explain and characteristics of Protisia? It's the kingdoms. What is the ratio of carbon atoms to hydrogen atoms in a saturated cyclic hydrocarbon? the office of price administration had the authority to control wages and set maximum prices. what was another form of economic control? BRAINLIEST!!!Which statement about a dilation with a scale factor of 3 is true? Fill in the blanks below: The flow of electricty is similar to the movement of water through a pipe. The movement is the __________, the force of the current is the __________, and the rate of the current is the __________. For electricy to move it requires a complete __________ so the electricty can flow both in and out. A. Circuit, Amps, Volts, Current B. Circuit, Volts, Amps, Current C. Current, Volts, Amps, Circuit D. Smooth, Power, Amount, System solve the exponential equation[tex] {10}^{ - x} = {7}^{4x} [/tex] People might be motivated to move away from the countries of origin for many reasons, known as push factors. Similarly, people are also drawn to a certain country for many other reasons, known as pull factors. In the table below, list a few ideas of what my constitute a push factor for leaving one country in a few ideas of what might be a pull factor drawing someone into a new country.Pleassseee helpp!!! Write a balanced equation for the complete combustion of glucose (c6h12o6). oxygen gas is the other reactant in this combustion reaction. the products are co2 and h2o. write a balanced skeleton equation for this reaction. how did the rights of citizens change in the Philippines after Fredinand marcos was elected presidentA. Citizens gained freedom of speech.B. Citizens who had been exiled return.C. Citizens now voted in regular elections.D. Citizens launch their basic freedoms. Which of these was the MAIN reason Andrew Johnson was not convicted after he was impeached? A) Senate Democrats blocked the vote from taking place. B) He resigned as President before the Senate could vote. C) The Civil War ended before the vote was scheduled to take place. Eliminate D) Some Republicans did not want to upset the balance of government. The maximum number of electrons in a p sub-level is: PLZ Help me!!! 20 Points! Plz, know the answers!Jack needs to save $125 to go to a concert. He has saved $35. He makes $7.50 an hour at his job. With x representing the number of hours, which equation and solution can be used to show how many hours Jack must work in order to have enough money to go to the concert? A. 125x + 35 = 750; x = 5.75 B. 35x + 125 = 750; x = 18 C. 7.5x + 35 = 125; x = 12 D. 357.5x=125;x=6 What is the slope of this line? how did the people of east and west berlin react to the wall coming down? Identify the root and its meaning for the following word. heliocentric Evaluate: 18.4 2.3 3.4 + 13.812 =