The half life of radium is 1690 years. if 80 grams are present now, how much will be present in 830 years

Answers

Answer 1

Answer:

A(t) = amount remaining in t years

      = A0ekt, where A0 is the initial amount and k is a constant to                     be determined.  

Since A(1690) = (1/2)A0 and A0 = 80,

                we have 40 = 80e1690k

                1/2 = e1690k

                ln(1/2) = 1690k

                k = -0.0004

So, A(t) = 80e-0.0004t

Therefore, A(430) = 80e-0.0004(430)

                           = 80e-0.172

                           ≈ 67.4 g

Step-by-step explanation:


Related Questions

What is the volume of this object?
__u3

Answers

Answer:

15u³

Step-by-step explanation:

To find volume ↓

Volume

= length × width × height

= 2u × 2½u × 3u

= 15u³

Hope this helps =)

help me pwesssssssssss

Answers

Answer:

858 Remainder 4

Step-by-step explanation:


Please use cofunction or even odd identities to solve this problem!

50 points !

Answers

Answer:

  cot(θ) = -1.45

Step-by-step explanation:

The identity applicable to this problem is ...

  tan(π/2 -θ) = cot(θ)

__

Substituting for tan(π/2 -θ), you have the desired cotangent value:

  cot(θ) = -1.45

Nine of the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 are to be put in two groups so that the sum of the numbers in each group is a multiple of four.

What is the largest number that could be left out?

Answers

Answer:

13,62,75,48,1092

Step-by-step explanation:

1+3=4, 6+2=8, 7+5=12, 4+8=12& 1+0+9+2=12.

Use the shell method to write and evaluate the definite integral that represents the volume of the solid generated by revolving the plane region about the y-axis.
y = 3 − x

Answers

The volume of the solid generated by revolving the plane region y=3−x about the y-axis is 9π cubic units.

What is integration?

It is defined as the mathematical calculation by which we can sum up all the smaller parts into a unit.

We have a function:

y = 3 - x

From the graph:

Shell radius = y

Height = 3 - y

From the shell method, we can write the integral as follows:

[tex]\rm Volume =2\pi\int\limits^0_{-3} {y(3-y)} \, dy[/tex]

[tex]\rm Volume =2\pi\int\limits^0_{-3} {(3y-y^2)} \, dy[/tex]

After solving the above definite integral, we will get volume:

Volume = 9π cubic units

Thus, the volume of the solid generated by revolving the plane region y=3−x about the y-axis is 9π cubic units.

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I don't know the answer ccuh

Answers

Answer:

  minor arc

Step-by-step explanation:

This is a vocabulary question:

major arc: has a measure more than 180°minor arc: has a measure less than 180°semicircle: has a measure of exactly 180° (connects the ends of a diameter)

__

Arc EA is a minor arc.

_____

Additional comment

In general, unless the two named points are the ends of a diameter, the arc is a minor arc. A major arc will generally be defined by designating a third point on the long arc connecting the same points on the circumference. For example, EDA, ECA, and EBA all designate the major arc connecting points E and A. (We can also use the descriptor, "major arc EA.") Without any of these extras designating the major arc, EA is considered to be the minor arc.

A pizza dough recipe has a ratio of 5 cups of flour to 2 cups of water. There are ?
cups of flour per cup of water

Answers

Answer:

2.5 cups of flour per cup of water.

Step-by-step explanation:

We can divide the entire recipe by two, to get the amount of flour to 1 cup of water.

5/2 = 2.5

2/2 = 1

Therefore, 2.5 cups of flour needs 1 cup of water.

Answer:

There are 2.5 cups of flour per cup of water

Step-by-step explanation:

Step 1:  Find the ration

Cups of Flour : Cups of Water

5 : 2

2.5 : 1

Answer:  There are 2.5 cups of flour per cup of water

NEED THIS ASAP
Which statement describes (²) ?
n=1
The series diverges because it has a sum of 1.
O The series converges because it has a sum of 1.
O The series converges because it has a sum of 4.
The series diverges because it does not have a sum.

Answers

Answer:

option b

please mark me as brainliest

Answer: the series converges because it has a sum of 1 (b)

Step-by-step explanation:

bec i said so

Pls help me in this khan academy exercise

Answers

Answer:

x= 180° - (103°+33°)

x= 180° - 136°

x= 44°

Determine the equation for a circle in standard form with a radius of 18, and center (18,-18).

Answers

Answer:

(x-18)²+(y+18)²=18².

Step-by-step explanation:

1) the formula is: (x-x₀)²+(y-y₀)²=r², where (x₀;y₀) - coordinates of the centre, r - the length of the radius;

2) according to the formula above:

(x-18)²+(y+18)²=18².

Find the area of the figure.

(50 POINTS On Last post)

Answers

Answer:

173,056,00

Step-by-step explanation:

You pick a card at random.
1 2 3 4
567
What is P(not even)?
Write your answer as a fraction or whole number.

Answers

Answer:

p7

Step-by-step explanation:

If it includes 4 then 0.8, if not then 0.6.

Let Vector f = LeftAngleBracket 4, 3, 7 RightAngleBracket. and Vector g = LeftAngleBracket negative 1, 0, 2 RightAngleBracket. . Which graph shows Vector f + vector g. ?

Answers

Vectors simply means a quantity that has both magnitude and direction but not position e.g acceleration.

What is a vector?

Your information is incomplete as the graphs aren't given. Therefore, an overview of vectors will be given.

In this case, vectors simply means a quantity that has both magnitude and direction but not position e.g acceleration, velocity, etc.

A vector can also be an element of the vector space. The direction is typically equal to the angle formed with the x-axis.

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Question 13
You deposit $8,400 in an account earning 3.6% interest compounded monthly.
a. How much will you have in the account in 20 years?
b. How much interest will you earn?

Answers

Answer:

A = $17,238.65

I (interest) = $8,838.65

Step-by-step explanation:

Using the formula A = P(1 + r/n)^nt

A = $17,238.65

A = P + I where

P (principal) = $8,400.00

I (interest) = $8,838.65

First, convert R as a percent to r as a decimal

r = R/100

r = 3.6/100

r = 0.036 rate per year,

Then solve the equation for A

A = P(1 + r/n)^nt

A = 8,400.00(1 + 0.036/12)^(12)(20)

A = 8,400.00(1 + 0.003)^(240)

A = $17,238.65

Summary:

The total amount accrued, principal plus interest, with compound interest on a principal of $8,400.00 at a rate of 3.6% per year compounded 12 times per year over 20 years is $17,238.65

The ceiling of Stacy's living room is a square that is 22 ft long on each side. Stacy knows the diagonal of the ceiling from corner to corner must be longer than 22 ft, but she doesn't know how long it is.

Solve for the length of the diagonal of Stacy's ceiling in two ways:

(a) Using the Pythagorean Theorem.

(b) Using trigonometry.

Round each answer to the nearest whole number and make sure to show all your work. (Hint: the answers should be the same!)

Answers

Answer:

I don't understand trig very well but I do get pythagorean theorem, which I can help with. Your final answer will end up being 31.

Step-by-step explanation:

First off the formula for pythagorean theorem is a^2 + b^2 = c^2

We know that C stands for the hypotenuse so we want to know what C is.

A and B are both 22 so our equation turns into 22^2 + 22^2 = c^2

22 squared is 484 which leads to 484 + 484 = c^2

484 + 484 = 968

968 is our C^2 but we still need to find the square root

The square root of 968 is 31.11269837... and a whole lot of other numbers

You round that out to 31 and get the length of your diagonal

what is the simplest form of 2/3 - 1/4 =

Answers

Answer:

I got 5/12

Step-by-step explanation:

Hope this helped

ANSWER

The answer will be

Step-by-step explanation:

5/2=0•416666667

3 Select the correct answer. How can you write the expression 7(b – 2) in words? A. two subtracted from the quotient of seven divided by b B. seven added to difference of b minus two C. the quotient of seven divided by b minus two D. two subtracted from seven times b E. the product of seven and the difference of b minus two

Answers

Answer:

option E is correct.

Step-by-step explanation:

from the options, the correct answer is:

the product of seven and the difference of b minus two.

HOPE THIS HELPSPLEASE RATE AND MARK BRIANLIEST!!!

Which expression shows 48 + 36 written as a product of two factors

Answers

Answer:

12(4+3)

Step-by-step explanation:

use this dataset for the next three questions: 5, 10, 12, 4, 6, 11, 13, 5 1. Calculate the mean. 2 Ultimate Medical Academy.
calculate the mean​

Answers

Answer:

11.8

Step-by-step explanation:

5 + 10 + 12 + 4 + 6 + 11 + 13 + 51= 118

The average (mean) is equal to the sum of all the data values divided by the count of values in the data set.

Count = 10

Sum = 118

Average = Sum / Count

118/10= 11.8

The cost of gas increases monthly at a rate of 3.2%. If gas cost $1.75 today. How much will it cost in 3 years? ( round to the nearest cent (2 decimal places) )

Answers

Answer:

$1.92

Step-by-step explanation:

present cost = $1.75

time = 3 years

rate = 3.2%

cost after three years = present cost (1 +[tex]\frac{R}{100}[/tex] )^3

=$1.75 ([tex]\frac{103.2}{100}[/tex])^3

=$1.75*1.099

=$1.92

Threrefore , after 3 years cost of gas will be $1.92.

Skylar wanted to show the proportional relationship between the dollar value of the original investment, x, and its value after a 10% decrease, y. He creates the table of values shown. Does it model the relationship? Explain. Then, provide a correct equation for the relationship Skylar wants to model.

Answers

After checking the information of the table, it is to notice that the table fulfills the behavior of a direct relationship described by the linear equation y = 0.9 · x. #SPJ1

How to analyze a relationship between the two variables

Let be x and y the original investment and the value after applying the change, both in monetary units. A direct relationship is observed by following this model:

y = (1 + r/100) · x     (1)

Where r is change rate, in percentual units.

After checking the information of the table, it is to notice that the table fulfills the behavior of a direct relationship described by the linear equation y = 0.9 · x. #SPJ1

Remark

The table of the change in investment with respect to initial investment is missing and is now introduced below:

(x₁, y₁) = (75, 7.5), (x₂, y₂) = (100, 10), (x₃, y₃) = (200, 20), (x₄, y₄) = (300, 30), (x₅, y₅) = (400, 40)

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a food server at harpers restaurant earns 5 dollars plus a 15% tip on the money made on each table he serves. Sam worked as a food server for six hours last friday and his tables earned $600. How much money did Sam make that day?

Answers

Answer:

The answer is given in the picture

Step-by-step explanation:

Do you remember me calista

I am alvena

Answer:

$70

Step-by-step explanation:

$5 x 6 hours = $30

$600 ÷ 15% = $40

$30 + $40 = $70

PLEASE HELP!!!!!
Abigail is studying for the school spelling bee. She already knows 204 words from the vocabulary list. Each day, she learns
24 additional words from the vocabulary list.
Which equation can be used to determine the total
number of words Abigail knows from the vocabulary list, y, over x days?
• A. y=24-204
•b y=24+204
• y=24(x+204)

Answers

Answer:

I think that it is y=24(x+204)

y= x24 + 204
okay so x is the number of days and you would multiply that by 24 because that’s how many words she learns each day and you would add 204 because that’s how many words she already knows. hope this helps

f(x) = 2x + 3 and g(x) = 24 – X.

Solve the equation f(x) = g(14).

Answers

Answer:

x = 3.5

Step-by-step explanation:

f(x) = 2x + 3

g(x) = 24 – x

-> g(14) = 24 - 14

-> g(14) = 10

f(x) = g(14) (Given)

-> 2x + 3 = 10

-> 2x = 10 - 3

-> 2x = 7

-> x = 7/2

-> x = 3.5

Find the distance between the points (7,14) and (18,5).

Answers

Answer:

Exact distance = [tex]\sqrt{202}[/tex]

Approximate distance = 14.2127

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

Work Shown:

[tex](x_1,y_1) = (7,14) \text{ and } (x_2, y_2) = (18,5)\\\\d = \sqrt{(x_1 - x_2)^2 + (y_1 - y_2)^2}\\\\d = \sqrt{(7-18)^2 + (14-5)^2}\\\\d = \sqrt{(-11)^2 + (9)^2}\\\\d = \sqrt{121 + 81}\\\\d = \sqrt{202}\\\\d \approx 14.2127\\\\[/tex]

Note: I used the distance formula. Though you could plot the points, form a right triangle, and use the pythagorean theorem as an alternative route. The distance formula is effectively a modified version of the pythagorean theorem.

You need a 55% alcohol solution. On hand, you have a 50 mL of a 25% alcohol mixture. You also have 60% alcohol mixture. How much of the 60% mixture will you need to add to obtain the desired solution?

Answers

Answer:

  300 mL

Step-by-step explanation:

There is a simple diagrammatic way to solve mixture problems, illustrated in the attachment. In the left column are the available solution percentages. In the center is the percentage of the desired mix. In the column to the right of that are the diagonal differences between the desired value and the constituent values. Those differences represent the proportions of the constituents on the same horizontal line.

__

Here, that means 30 parts of 60% solution are needed for 5 parts of 25% solution. Since we have 50 mL of 25% solution, we can multiply these ratio values by 10 mL to find the quantities needed. That has been done here in the right-most column.

300 mL of 60% solution are needed to obtain the desired mixture.

__

Additional comment

If you want to write an equation, you can let x represent the quantity of high-concentration solution needed. Then the amount of alcohol in the mix is ...

  0.60x +0.25(50) = 0.55(x +50)

  0.05x = 0.30(50) . . . . . . . subtract 0.55x+0.25(50)

  x = 300 . . . . . . . . . . . . mL of 60% solution needed

NO LINKS!!

Determine if each statement is always, sometimes, or never true​

Answers

Answer:

sometimessometimesalways

Step-by-step explanation:

These questions can be answered by reference to the formulas for the volume of a cone, cylinder, and sphere.

__

Cone

  V = 1/3πr²h . . . volume depends on height as well as radius

Cones with the same radius will sometimes have the same volume. (When they have the same height.)

__

Cylinder

  V = πr²h . . . volume depends on height as well as radius

Cylinders with the same radius will sometimes have the same volume. (When they have the same height.)

__

Sphere

  V = 4/3πr³ . . . volume depends only on radius

Spheres with the same radius will always have the same volume.

SometimesSometimesAlways

Lets note the formulas first to make clear.

For cone

V=1/3πr²h

For cylinder

V=πr²h

For sphere

V=4/3πr³

We can see

for first two

the volume depends upon the height hence if they have same radius then their volume may or may not be same

For sphere

volume depends upon radius so if radius is same the volume is same

Which graph represents the function f(x) = 1/3|x|?​

Answers

Answer:

The answer is D.

Step-by-step explanation:

Question 7 of 10
How many different roots does the polynomial function, y = (x - 2)(+3)
have?
O A. 4
B. 3
O c. 2
O
D. 1
SUBMIT

Answers

c. 2

you should just get an app on ur phone its easier than asking here

Two different roots the given polynomial function have. Therefore, option C is the correct answer.

What is the solution of a quadratic equation?

The solutions to the quadratic equation are the values of the unknown variable x, which satisfy the equation. These solutions are called roots or zeros of quadratic equations. The roots of any polynomial are the solutions for the given equation.

The given equation is y=(x-2)(x+3)

The roots (zeros) are the x values where the graph intersects the x-axis. To find the roots (zeros), replace y with 0 and solve for x.

Here, (x-2)(x+3)=0

(x-2)=0 and (x+3)=0

x=2 and x=-3

Therefore, option C is the correct answer.

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"Your question is incomplete, probably the complete question/missing part is:"

How many different roots does the polynomial function, y = (x - 2)(x+3)?

A. 4

B. 3

C. 2

D. 1

If x is 6 and y is -2 what’s the value of yx

Answers

Answer:

-12

Step-by-step explanation:

(6)(-2)= -12

6 multiply -2 equals 12.

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