The half-life of a radioactive substance is the time it takes for a quantity of the substance to decay to half of the initial amount. The half-life of the radioactive gas radon is approximately 2.8 days. The initial amount of radon used in an experiment is 74 grams. If N represents the number of grams of radon remaining t days after the start of the experiment,

Answers

Answer 1

Answer:

  N = 74(1/2)^(t/2.8)

Step-by-step explanation:

The exponential function expressing a half-life relation can be written ...

  amount = (initial amount) × (1/2)^(t/(half-life))

For the numbers given in this problem, this is ...

  N = 74(1/2)^(t/2.8)

__

Some folks like to express these relations in the form ...

  N  = 74e^(-kt)

In this form, the value of k is ...

  k = ln(2)/(half-life) ≈ 0.693147/2.8 ≈ 0.24755

  N = 74e^(-0.24755t)


Related Questions

Friction creates heat and lowers the _______

Answers

Answer:

energy

Step-by-step explanation:

Answer:

energy

Step-by-step explanation:

find the highest common factor (HCF) of 30 and 45

Answers

Answer:

The highest common factor of 30 and 45 is 15.

Step-by-step explanation:

factors of 30 = 1, 2, 3, 4, 5, 6, 10, 15, 30 ; factors of 45 are = 1, 3, 5, 9, 15, 45)

Greatest common factor is 15

Answer:

15.

Step-by-step explanation:

HCF is also called GCD. So, you divide both numbers with a common number that can divide both numbers at the same time without a remainder.

     3    30         45

      5    10          15

            2             3

3 × 5 = 15

What is the area of the shaded sector of the circle? 20pi units squared 40pi units squared 180pi units squared 400

Answers

The area of the sector with a radius of 20 units and a central angle of 162° is 180π unit².

What is the sector of a circle?

A sector is the portion of a circle enclosed by two radii and an arc, where the smaller area is known as the minor sector and the larger is the major sector.

The radius of the sector =20 units

Central angle subtended by sector = 162° = 162π/180 radians

As we know the area of a sector= 0.5r²α

where r is the radius and α is the central angle.

So, the area of the given sector = 0.5*20²* 162π/180

The area of the given sector = 180π unit²

Therefore, The area of the sector with a radius of 20 units and a central angle of 162° is 180π unit².

To get more about the sector visit:

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Answer:

its c

Step-by-step explanation:

what is the surface area of the a cylinder with base radius 3 and height 8.​

Answers

Bonjour,

πr² *h

3,14 * 3² *8

= 3,14 *9 *8

=>226, 08 ....²

Answer:

66π square units

Step-by-step explanation:

David’s family is driving from New York to Florida. They know the distance they will travel is about 1100 miles. If a map has a scale of 1 in. = 80 mi, about how far will the trip be on the map? StartFraction 8 over 110 EndFraction inches 11 inches 13 and three-fourths inches 88 inches.

Answers

Answer:

  13 and three-fourths inches

Step-by-step explanation:

The map distance can be found using a proportion with the map scale.

__

  map distance / (1100 mi) = (1 in) / (80 mi)

  map distance = (1100×1)/80 in = 13 3/4 in . . . multiply by 1100 mi; cancel mi

The trip will be about 13 3/4 inches on the map.

A lake has a surface area of 11. 0 square miles. What is its surface area in square meters?

Answers

Answer:

11mi² = 28489869m²

Step-by-step explanation:

m² = mi² / 0.00000038610

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Answers

Step-by-step explanation:

For question 22: Notice the congruent symbol on sides AB and CB; this shows that the triangle is isosceles, and in an isosceles triangle, the angles opposite congruent sides are congruent. Thus, angle A actually equals angle C.

In other the find B, it is know that all of the interior angles of a triangle must add to 180; thus, this can be written as: angle A + angle B + angle C = 180.

Since you already know angles A and C, subtract angle A and angle C from 180 to get angle B.

For question 23:

Notice that triangle DBC is an isosceles triangle, and that angle D and angle C are opposite of congruent sides, indicating that they are equal. Since the interior angles of a triangle must add up to 180, and you know that angle D equals angle C, you can find angle DBC by doing 180 - (2 * angle D).

Now that you have angle DBC, you can find angle CBA; since these two angles form a straight line, you know they must add to 180 degrees. Thus, 180 - angle DBC equals angle CBA.

Now, notice that triangle CBA is also isosceles, and that angles CBA and angle A are opposite congruent sides, indicating that they are also congruent. Thus, angle A equals angle CBA.

Hope this helps :)

So if I have 6,000 dollars and I need 20,000 how much money do I need to earn to reach 20,000?​

Answers

Answer14,000

Step-by-step explanation:

20,000-6,000=14,000

Answer:14000

Step-by-step explanation:

20000 - 6000, not sure why ur doing these type of problems in highschool

What is the volume of the prism?

Enter your answer in the box as a mixed number in simplest form.
A rectangular prism with the width as three and a half feet, the length as two and a half feet and the height as one and a half feet. i need help

Answers

Answer:

The volume is approximately 13 1/8 feet.

Step-by-step explanation:

Volume of a rectangular prism is calculated by multiplying the width, length, and height together.

3.5w × 2.5l × 1.5h = 13.125

13.125 = 13 1/8. The fraction cannot be reduced any further, so this is its simplest form.

wich one' is the right answer need help

Answers

Answer:

C

Step-by-step explanation:

because density equal all the rest

a + b =c a + b + c = 36 given that a and b have the same value what is a,b and c

Answers

Answer:

a = 9    b = 9    c = 18

Step-by-step explanation:

a+b = c

a+ b + c = 36        but we know   a+b = c   sub that in

  c    + c = 36

       c = 18             now  a + b = c    and a and b are the same

                                   so  a and b are = 9

Answer:

a is 9

b is 9

c is 18

Step-by-step explanation:

Let's list the information provided

a + b =c

a + b + c = 36

a=b

Knowing that a=b we can replace b with a in the equations

a+a is the same as 2a since a is being doubled

2a=c

Knowing this we can replace c with 2a

2a+2a=36

Now solve for a

[tex]2a+2a=36\\4a=36\\\frac{4a}{4} =\frac{36}{4} \\a=9[/tex]

Now let's sub this value of a into the equations to see what the other values are

a=b

9=b

2a=c

2(9)=c

18=c

PLEASE HELP I NEED TO TURN THIS IN QUICKK

Answers

Answer:

QUienn quieres ser mi ami

Step-by-step explanation:

xd

what are the solutions to the equation?

Answers

Answer:

x = -2 and 1

Step-by-step explanation:

Given :

f(x) = x+2

g(x) = -x²+4

The solution to the equation f(x) = g(x)

=> x+2 = -x²+4

=> x²+x = 4-2

=> x²+x -2 = 0

By factorisation

=> x²+2x-x -2 = 0

=> x(x+2) -1(x+2)

=> (x+2) (x-1)

x = -2 and 1

SOOO CLOSEE TO BEING DONEEEE helppppp

Answers

[tex]423 \times 10 {}^{2} [/tex]

[tex]2 \times 10 {}^{3} [/tex]

[tex]92 \times 10 {}^{5} [/tex]

[tex]4 \times 10 {}^{3} [/tex]

[tex]80 \times 10 {}^{6} = 8 \times 10 {}^{7} [/tex]

[tex]32 \times 10 {}^{9} [/tex]

Answer:

4.23*10^4

2*10^3

9.2*10^7

4*10^3

8*10^7

3.2*10^10

Multiplication and __are inverse operations. addition subtraction O division​

Answers

Answer:

Division is the opposite of multiplication

Step-by-step explanation:

Opposites:

Addition and subtraction

multiplication and division

differentiation and integration.

A triangle has angles measureing 40 and 30. What is the measure of the third angle

Answers

Answer: 110 degrees

Step-by-step explanation:

The sum of the angles of a triangle is 180 degrees, so the third angle is 180-40-30=110 degrees.

Is the following relation a function yes or no

Answers

It's function of sinus

...........

Hello, the point (-2,k) lies on the line. Determine the value of k. please answer this. ty

Answers

Answer:

0

Step-by-step explanation:

This problem is impossible if the x value is -2. However, if the x value is 2, find where the line meets x=2 and record the y value.

help me please thank you​

Answers

Answer:

o = 20.18; b = 13.51i = 12.68; n = 27.19

Step-by-step explanation:

The mnemonic SOH CAH TOA reminds you of the relations between sides and trig functions in right triangles. These can be used to solve the triangles shown.

__

1.

  Sin = Opposite/Hypotense

  sin(48°) = 15/o

  o = 15/sin(48°) ≈ 20.18 . . . . . . . . . multiply by o/sin(48°)

  Cos = Adjacent/Hypotenuse

  cos(48°) = b/o

  b = o·cos(48°) = 20.18·cos(48°) ≈ 13.51

For triangle BOX, o = 20.18, b = 13.51.

__

2.

  Sin = Opposite/Hypotense

  sin(25°) = i/30

  i = 30·sin(25°) ≈ 12.68

  Cos = Adjacent/Hypotenuse

  cos(25°) = n/30

  n = 30·cos(25°) ≈ 27.19

For triangle TIN, i = 12.68, n = 27.19.

A triangle has sides with lengths of 63 miles, 64 miles, and 85 miles. Is it a right triangle? Yes or no?

Answers

Answer:

no it is not a right angled triangle.

Step-by-step explanation:

forthetra

This is a pythagorean theory question

If this is a right triangle (meaning one of the angles in the triangle is 90 degrees) then the lengths of the sides should make the formula true.

a^2 + b^2 = c^2 (c being the longest side or hypotenuse)

so plug in the lengths and prove or disprove the statement.

(63)^2 + (64)^2 = (85)^2

3969 + 4096 = 7225

8065 = 7225 false

The answer is NO it is not a right triangle.

I hope this helps and is the BRAINLIEST!

Good luck with your studies!

Can anyone solve this correctly?

Answers

Answer:

  24 cm³

Step-by-step explanation:

The volume of a triangular prism with triangular face 4 cm by 2 cm and height 6 cm is the product of the triangle area and the prism height:

  V = BH

  V = ((1/2)bh)H = 1/2(2 cm)(4 cm)(6 cm) = 24 cm³

The volume of the prism is 24 cubic centimeters.

_____

Additional comment

Note that this is half the volume of a rectangular prism of the same dimensions.

help please and please hurry this assignment is due 11:59

Answers

You find the area of trapezium: 45
Then lower shape, triangle: 13.5
Then you add both:
B) 58.5 square feet:))

An electrician has an income of $41,500. The income tax the electrician has to pay is 12%. What is the amount of income tax that the electrician has to pay? A) $3,840 B) $4,164 C) $4,980 D) $5,210.

Answers

Answer:

he has to pay 4980$ in tax So its C) 4,980

The amount of income tax that the electrician has to pay is $4980. Then the correct option is C.

What is the percentage?

The amount of something is expressed as if it is a part of the total which is a hundred. The ratio can be expressed as a fraction of 100. The word percent means per 100. It is represented by the symbol ‘%’.

An electrician has an income of $41,500.

The income tax the electrician has to pay is 12%.

Then the amount of income tax that the electrician has to pay will be

Amount of income tax = 0.12 × $41500

Amount of income tax = $ 4980

Thus, the amount of income tax that the electrician has to pay is $4980.

More about the percentage link is given below.

https://brainly.com/question/8011401

If the circumference is 50 cm what is radius of the circle?

Answers

Answer:

7.96

Step-by-step explanation:

C=2πr undo it

R=C/2π=50/2×π≈7.5775 rounded is 7.96

Hope this helps!

Have a nice day!! :D

The radius of the circle is 7.96 cm.

What is the radius of the circle?

The radius of a circle is the distance from the center of the circle to any point on its circumference. It is usually denoted by ‘R’ or ‘r’.

The circumference of the circle is given by;

[tex]\rm Circumference = 2\pi r[/tex]

Where r is the radius of the circle.

Substitute all the values in the formula

[tex]\rm Circumference = 2\pi r\\\\50 = 2\pi r\\\\r = \dfrac{50}{2\times 3.14}\\\\r=7.96[/tex]

Hence, the radius of the circle is 7.96 cm.

To know more about the radius of the circle click the link given below.

https://brainly.com/question/11137975

what are the slope and y - intercept of the equation 6x+3y=-12

Answers

Answer:

Slope= -2

y-intercept= -4

Step-by-step explanation:

To find the slope and y-intercept of a given equation, first rearrange the equation such that it is in the slope-intercept form. In the slope-intercept form, the coefficient of y is 1 and the rest are moved to the left hand side of the equation.

[tex]\textcolor{steelblue}{\text{Slope-intercept form}}[/tex]

y= mx +c, where m is the slope and c is the y-intercept

Given equation: 6x +3y= -12

Let's leave the y term on the left of the equation and bring the rest to the right.

3y= -6x -12

To ensure that the coefficient of y is 1, divide both sides by 3.

y= -2x -4

The equation is now in the slope-intercept form.

The slope is the coefficient of x (the number that comes before x), thus the slope is -2. The y-intercept is -4.

help! please! now!.............

Answers

Answer:

The answer is 133.5

Step-by-step explanation:

See the image above

Which expression is equivalent to Cosine (StartFraction pi Over 2 EndFraction r) for all values of r?.

Answers

The expression that is equivalent to [tex]Cos(\frac{\pi }{2}+r )[/tex] is [tex]-Sinr[/tex].

Given trigonometric expression is:

[tex]Cos(\frac{\pi }{2}+r )[/tex]

What is the value of [tex]Cos(\frac{\pi }{2}+\theta )[/tex]?

The value of [tex]Cos(\frac{\pi }{2}+\theta )[/tex] is [tex]-Sin\theta[/tex] because [tex]\frac{\pi }{2} +\theta[/tex] lies in the second quadrant and the cosine function is negative in the second quadrant.

So, [tex]Cos(\frac{\pi }{2}+r )= -Sin r[/tex]

The range of sine and cosine functions is the same i.e. [-1,1].

Both the functions are periodic functions with periods 2π.

Hence, the expression that is equivalent to [tex]Cos(\frac{\pi }{2}+r )[/tex] is [tex]-Sinr[/tex].

To get more about trigonometric functions visit:

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25 cows produce 4 2/3 literes of milk how much milk is this in total

Answers

Answer:

116 2/3 liters of milk

Step-by-step explanation:

4 2/3 liters of milk per cow * 25 cows = 350/3 liters of milk = 116 2/3 liters of milk

I hope this was good enough. Happy mathing!

Blue Tide Swim Shop is having its annual summer sale, when every item in the store gets marked down. During the sale, rashguards sell for $5 less than full price. Miguel purchases 3 rashguards and pays a total of $60.
Which equation can you use to find how much money, f, each rashguard costs at full price?
How much does each rashguard cost at full price?

Answers

Original price be x

Discount price be y

The equation is

y=x-5

So

y=3(x-5)60=3x-153x=75x=25$

Answer:

3(f - 5) = 60

$25

Step-by-step explanation:

Let f = full price of rash-guard

Given:

during the sale, rash-guards sell for $5 less than full pricecost of 3 rash-guards during sale is $60

Therefore, the equation you can use to find how much money each rash-guard costs at full price is:

3(f - 5) = 60

To calculate the full price of the rash-guard, solve the equation for f:

⇒ 3(f - 5) = 60

Expand:

⇒ 3f - 15 = 60

Add 15 to both sides:

⇒ 3f = 75

Divide both sides by 3:

⇒ f = 25

Therefore, the full price of each rash-guard is $25.

The relative frequency of Event A in an experiment is 13.


If the experiment is performed 30 times, how many times should you expect Event A to occur?


Enter your answer as a number, like this: 42


!!PLEASE HELP ME IM NOT GOOD AT MATH AT ALL!!

Answers

Based on the relative frequency and the number of times the experiment is to be performed, the number of times Event A should occur is 10 times.

How many times should Event A occur?

The relative frequency in this regard is 1/3.

The number of times it will occur can be found as:

= Relative frequency x Number of times event was performed

Solving gives:

= 1/ 3 x 30

= 10 times

Find out more on relative frequency at https://brainly.com/question/3857836.

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