Consider a radioactive substance with original weight 20grams given by W(x)= 20 x (0.95)^x, where W(x) is with weight after x years. In about how many years is the radioactive substance half of its original weight? Type answer to one decimal place.

Answers

Answer 1

Answer:

13.5 years

Step-by-step explanation:

We are given the expression:

W(x)= 20 x (0.95)^x

Where W(x) = 20grams/2

= 10 grams

Hence:

10 = 20 x (0.95)^x

Divide both sides by 20

10/20 = 20 x (0.95)^x/20

0.5 = (0.95)^x

Take the log of both sides

log 0.5 = log (0.95)^x

log 0.5 = x log (0.95)

Divide both sides by log 0.95

x = log 0.5 / log 0.95

x = 13.513407334 years

Approximately to 1 decimal place =✓13.5 years

Therefore, it will take 13.5 years for the radioactive substance to be half of its original weight.


Related Questions

Please help. How do you find cosine, sine, cosecant and secant with this triangle? ​

Answers

Hi there! You have to remember these 6 basic Trigonometric Ratios which are:

sine (sin) = opposite/hypotenusecosine (cos) = adjacent/hypotenusetangent (tan) = opposite/adjacentcosecant (cosec/csc) = hypotenuse/oppositesecant (sec) = hypotenuse/adjacentcotangent (cot) = adjacent/oppositecosecant is the reciprocal of sinesecant is the reciprocal of cosinecotangent is the reciprocal of tangent

Back to the question. Assuming that the question asks you to find the cosine, sine, cosecant and secant of angle theta.

What we have now are:

Trigonometric RatioAdjacent = 12Opposite = 10

Looks like we are missing the hypotenuse. Do you remember the Pythagorean Theorem? Recall it!

a²+b² = c²

Define that c-term is the hypotenuse. a-term and b-term can be defined as adjacent or opposite

Since we know the value of adjacent and opposite, we can use the formula to find the hypotenuse.

10²+12² = c²100+144 = c²244 = c²

Thus, the hypotenuse is:

[tex] \large \boxed{c = 2 \sqrt{61} }[/tex]

Now that we know all lengths of the triangle, we can find the ratio. Recall Trigonometric Ratio above! Therefore, the answers are:

cosine (cosθ) = adjacent/hypotenuse = 12/(261) = 6/61 = (661) / 61sine (sinθ) = opposite/hypotenuse = 10/(261) = 5/61 = (561) / 61cosecant (cscθ) is reciprocal of sine (sinθ). Hence, cscθ = (261/10) = 61/5secant (secθ) is reciprocal of cosine (cosθ). Hence, secθ = (261)/12 = 61/6

Questions can be asked through comment.

Furthermore, we can use Trigonometric Identity to find the hypotenuse instead of Pythagorean Theorem.

Hope this helps, and Happy Learning! :)

What is the area of the figure composed of a parallelogram, a square, and a rectangle?
10 in.
3.5 in.
4 in.
6 in.
12,5 in.

Answers

Area of parallelogram = 10 * 3.5 = 35. Area of the square = 4*4 = 16.

A studio apartment has a floor that measures 120 feet by 60 feet. A scale drawing of the floor on grid paper uses a scale of 1 unit : 6 feet. What are the dimensions of the scale drawing?

Answers

Answer: [tex]20\ \text{unit}\times 10\ \text{unit}[/tex]

Step-by-step explanation:

Given

A studio apartment has a floor that measures [tex]120\ ft \times 60\ ft[/tex]

Scale used is 1 unit:6 feet i.e 6 feet of actual floor is considered 1 unit in drawing

The dimension of scale drawing is [tex]\frac{1}{6}[/tex] of actual

Dimensions are

[tex]\Rightarrow \dfrac{120}{6}\times \dfrac{60}{6}\\\\\Rightarrow 20\ \text{unit}\times 10\ \text{unit}[/tex]

what expression is equivalent to x^2-7x+12+(x-3)^2

Answers

Answer:

2x²−13x+21

Step-by-step explanation:

Hope this answer helps you :)

Have a great day

Mark brainliest

Factor the following, I will give 5 stars and thanks.

Answers

Answer:

5) [tex]x=3,-1[/tex]

6) [tex]r=-6,-4[/tex]

7) [tex]p=2,3[/tex]

8) [tex]n=-4,8[/tex]

Step-by-step explanation:

5) [tex](x-3)(x+1)=0[/tex]

   [tex](3-3)(-1+1)=0[/tex] substitute x for a number that will make the statement true.

6) [tex](r+6)(r+4)=0[/tex]

   [tex](-6+6)(-4+4)=0[/tex] substitute r for a number that will make the statement true.

7) [tex](p-2)(p-3)=0[/tex]

   [tex](2-2)(3-3)=0[/tex]  substitute p for a number that will make the statement true.

8) [tex](n+4)(n-8)=0[/tex]

   [tex](-4+4)(8-8)=0[/tex] substitute n for a number that will make the statement true.

i need someone who could log into an acellus account and help solve 5 problems, they look something like this....( i will give 30 points)

Answers

Answer:

[tex]\huge\boxed{V=44cm^3}[/tex]

Step-by-step explanation:

(look at the picture)

The formula of a volume of a rectangular prism a × b × c:

[tex]V=abc[/tex]

We have two rectangular prisms.

[tex]1:\ 2cm\times2cm\times5cm\\2:\ 2cm\times2cm\times6cm[/tex]

Calculate the volume:

[tex]V_1=2\cdot2\cdot5=20(cm^3)\\\\V_2=2\cdot2\cdot6=24(cm^3)[/tex]

The volume of the irregular figure:

[tex]V_F=V_1+V_2\\\\V_F=20cm^3+24cm^3=44cm^3[/tex]

Ashley uses a mix of six base-ten blocks to model a 3 digit number. All 3 digits of the number are the same. What is the number?

Answers

Answer:

The number is 222

Step-by-step explanation:

The given parameters are;

The method Ashley models the 3 digit number = A mix of six base-ten blocks

The digits of the 3 digit number are equal

Therefore, given that in a 3 digit number, we have, hundreds, 100s, tens, 10s, and units, 1s, we can find the digits as follows;

Let 'x' represent the number of hundreds digits, let 'y' represent the number of tens digits and let 'z' represent the number of units digits, we have;

x = y = z...(1)

x + y + z = 6...(2)

Substituting the value of x = y, and x = z from equation (1), in equation (2), we get;

x + y + z = x + x + x = 6

∴ 3·x = 6

∴ x = 6/3 = 2

x = 2 = y = z

Therefore, the 3-digit numbers xyz = 222

How many units is this value from zero on the number line?
-8
answers
A. 16
B. 8
C. 0
D. -8
pls help urgent

Answers

Answer:

answer is 8

Step-by-step explanation:

hope this helps

It is -8 because you go backwards

Which of the following expressions is equal to squared +25? O A. (x+5012 O B. (x-50 O C. (x + 10 (x-151) O D. (X - 5)(x+51)​

Answers

Answer:

(x-5i)(x+5i)

Step-by-step explanation:

Given the expression

(x-5i)²

Expand

(x-5i)(x+5i)

= x² - 5ix + 5ix - 25i²

= x² - 25i²

Since i² = -1, hence;

(x-5i)(x+5i) = x² - 25(-1)

(x-5i)(x+5i) = x² + 25

Hence the required expression is (x-5i)(x+5i)

Matthew worked a summer job and saved $900 each
summer for the last 4 years. He also has been awarded a
grant in the amount of $5,000 and he received $3,000 in
scholarships. He estimated the first year of college to cost
$13,000. If he uses his savings, the grant, and his
scholarship, how much more will he need to pay for the
first year of college?

Answers

Answer:

1400

Step-by-step explanation:

hope that helps <3

What is the radius of this circle?

Answers

Answer:

radius is 9

Step-by-step explanation:

radius is half the diameter which is 18  and half of 18 is 9

9, radius is half of diameter therefore being 9.

Someone please help me out!!!

Answers

Answer:

[tex] \sin(c) = \frac{ab}{ac} \\ \sin(c) = \frac{36}{45} \\ \sin(c) = \ \frac{4}{5} [/tex]


[tex]3 + 9 - 2 12 \div 3[/tex]

Answers

3+9-212 divided by 3
Add the numbers and write the division as a fraction
12-12/3
Calculate the difference and the answer is
-176/3 (-176 over 3)
[Alternative Form would be
-58 2/3 or -58.6]

Kevin is 30 years old. He wants to take out a 15-year level term insurance policy with a face value of $500,000. The monthly premium is $56. What will be his total cost over the 15-year period?

Answers

Answer:

$10,080

Step-by-step explanation:

Monthly premium = $56

So, yearly premium = $56 × 12 = $672

Time period = 15 years

Now, we can calculate the total cost for 15 years period by using following formula,

Total cost = yearly premium × Time period

By putting the value, we get

Total cost = $672 × 15

= $10,080

Hence, total cost for 15 years period is $10,080.

What is the midline equation of the function g(x) = 2 cos(7x + 5) + 1?

Answers

Answer:

y = 1

Step-by-step explanation:

The midline of h(x) = 2 cos(7x + 5) is y = 0.

The graph of g(x) = 2 cos(7x + 5) + 1 is the same, except that the entire graph of h(x) is translated up by 1 unit.

Thus, the midline of g(x) = 2 cos(7x + 5) is y = 1.

Find the measure of the angle indicated

Answers

Answer:  B) 40 degrees

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

Explanation:

The arc measures shown are 138 and 58. Subtract the arc measures and divide by 2 to get the answer

(138-58)/2 = 80/2 = 40 degrees

The general formula is

(A - B)/2

where A and B are the arc measures. The value of A is always the larger arc measure. This formula works for two secant lines as this diagram shows, and it also works for a secant line and tangent line, and lastly it works if both lines were tangent.

A recipe for baba ghanoush cause for twice as much olive oil as lemon juice
Which expression represents the amount of olive oil needed for 4 tablespoons of lemon juice choose ALL that apply

A). 4•4
B). 4+2
C). 4•2
D). 4+4

Answers

Answer:

A. 4.4 I am doing good today

The answer is A and C

Basit played and online Pin Ball game the first time we got our score of 25000 point then he is called 125000 point and third time he scored 30000 what was his Score per game ?

Answers

Answer:

Average score per game = 60,000 per game

Step-by-step explanation:

Given:

Points scored in first game = 25,000

Points scored in second game = 125,000

Points scored in third game = 30,000

Find:

Average score per game

Computation:

Average = Sum of observation / Number of observation

So,

Sum of all game = 25,000 + 125,000 + 30,000

Sum of all game = 180,000

Number of games = 3

Average score per game = 180,000 / 3

Average score per game = 60,000 per game

can someone help me with these too please

Answers

Answer:

120 in³

Step-by-step explanation:

10 x 4 x 3 = 120

The hypotenuse of a right triangle is one inch longer than the longer leg. The shorter leg is seven inches shorter than the longer leg. Find the length of the hypotenuse.

Answers

Answer:

Length of hypotenuse is 13 unit or 5 unit

Step-by-step explanation:

Find;

Length of hypotenuse

Computation;

Assume;

Length of hypotenuse = h

Length of longer leg = h - 1

Length of shorter leg = h - 1 - 7

Using Pythagorean theorem

hypotenuse² = longer leg² + shorter leg²  

h² = (h - 1)² + (h - 1 - 7)²  

h² = (h - 1)² + (h - 8)²  

h² = h² - 2h + 1 + h² - 16h + 64  

h² = 2h² - 18h + 65

h² - 18h + 65 = 0

h² - 13h - 5h + 65 = 0

h(h - 13) -5(h - 13)

(h - 13)(h - 5)

So,

Length of hypotenuse is 13 unit or 5 unit

(I'm probably spammy lol)
More babes-
I just need help, like point me in the right direction, something.
I'm so tired-​

Answers

Answer:

x= 9

Step-by-step explanation:

85 + 2x +2 + {180 -(11x + 6) }=180 (sum of angles in a triangle)

87 + 2x + 180 - 6 -11x = 180

87 -9x - 6 = 0

81 = 9x

x= 9

What is the product of V3 and 2V30 in simplest radical form?

Answers

Answer:

Step-by-step explanation:

[tex]\sqrt{3[/tex] *2[tex]\sqrt{30[/tex]

2[tex]\sqrt{30*3}[/tex]

2[tex]\sqrt{3*3*2*5}[/tex]

2*3[tex]\sqrt{2*5}[/tex]

6[tex]\sqrt{10}[/tex]

At the donut shop the cost for a dozen donut holes and a glass of milk is $3.50. The cost for three dozen donut holes and four glasses of milk is $11.80 which pair of equations can be used to determine D (the cost for donut holes) and M (the cost for the milk)

Answers

Answer:

Step-by-step explanation:

12 D + M = 3.50

3*12 D +4M = 11.80

the pair of equations are

12 D + M = 3.50

36 D +4M = 11.80

Answer:

I need points lol 2=yx thank you for letting me spam

Find the the sum for the shown infinite geometric series?
2,2/3, 2/9, ...

Answers

Answer:

3

Step-by-step explanation:

The formula for the sum of an infinite geometric series is

[tex]\frac{a}{1-r}[/tex]

Where a is the first term and r is the common ratio. We can see that the first term is 2, and to find the common ratio, we can divide a term by the one before it. We can get:

[tex]\frac{\frac{2}{3}}{2} =\frac{2}{3} *\frac{1}{2}=\frac{1}{3}[/tex]

Now, we have all the values need to evaluate the formula. We can plug them in:

[tex]\frac{2}{1-\frac{1}{3} } \\\frac{2}{\frac{2}{3} } \\2*\frac{3}{2}\\3[/tex]

A bank makes a profit of 20 million euro. The bank pays 500 thousand euro in tax. What percentage of the profit is paid in tax?

Answers

Answer:

2.5%

Step-by-step explanation:

Given data

Profit = Euro 20,000,000

Tax paid= Euro 500,000

The percentage tax paid is

% Tax= Tax paid/Profit*100

% Tax= 500,000/20,000,000*100

% Tax=0.025*100

% Tax=2.5

Hence the percentage tax paid is 2.5%

I really need some help please ​

Answers

Answer:

y - 1 = 3/2(x - 4)

Step-by-step explanation:

plug in the given(known) x and y coordinates into the point-slope form:

=> y - 1 = 3/2(x - 4)

Find the area of the composite figure.

Answers

Answer:

Area of composite figure = 623.25 cm²

Step-by-step explanation:

Given:

Equal side of triangle = 39 cm

Diameter of semi-circle = 30 cm

Base of triangle = 30 cm

Find;

Area of composite figure

Computation:

Radius of triangle = 30 / 2

Radius of triangle = 15 cm

Height of triangle = √39² - 15²

Height of triangle = √1,521 - 225

Height of triangle = 36 cm

Area of composite figure = Area of semi-circle + Area of triangle

Area of composite figure = [πr² / 2] + [(1/2)(b)(h)]

Area of composite figure = [(3.14)(15)² / 2] + [(1/2)(15)(36)]

Area of composite figure = [(3.14)(225) / 2] + [(15)(18)]

Area of composite figure = [706.5 / 2] + [270]

Area of composite figure = 353.25 + 270

Area of composite figure = 623.25 cm²

Stephen kicked a ball inside. The equation that represents the height h in feet of the ball after being kicked and elapsed amount of time t in seconds

Answers

Answer:

The maximum height of the ball is: 14.0625ft

Step-by-step explanation:

The missing information is:

[tex]h(t) = 30t - 16t^2[/tex]

Required

The maximum height the ball attained

First, we calculate the time to reach the maximum height.

For a function: [tex]h(t) = at^2 + bt + c[/tex]

The maximum is: [tex]t = \frac{-b}{2a}[/tex]

So, the maximum of [tex]h(t) = 30t - 16t^2[/tex] is:

[tex]t = \frac{-b}{2a}[/tex]

Where

[tex]a = -16; b = 30[/tex]

So:

[tex]t = -\frac{30}{2*-16}[/tex]

[tex]t = -\frac{30}{-32}[/tex]

[tex]t = \frac{30}{32}[/tex]

[tex]t = 0.9375[/tex]

The maximum height is then calculated as:

[tex]h(t) = 30t - 16t^2[/tex]

[tex]h(0.9375) = 30 * 0.9375- 16 * 0.9375^2[/tex]

[tex]h(0.9375) = 28.125- 14.0625[/tex]

[tex]h(0.9375) = 14.0625[/tex]

A DrillingRick was diggingA well in the valley it dug to a point of -50 Meters in one day After 18 hours at how many meters would the rig be if it moved at the same amount each hour? Show your work.Explain your answer

Answers

Answer:

37.5 meters

Step-by-step explanation:

depth of well : hours of digging

it dug to a point of -50 Meters in one day

= 50 meters : 24 hours

After 18 hours at how many meters would the rig

Let

x = depth that will be rigged

depth of well : hours of digging

= x meters : 18 hours

Equate the ratios

50 meters : 24 hours = x meters : 18 hours

50/24 = x/18

50 * 18 = 24 * x

900 = 24x

x = 900/24

x = 37.5

x = depth that will be rigged = 37.5 meters

hey! i’ll give brainliest please help

Answers

Answer:

D

hope this helps

have a good day :)

Step-by-step explanation:

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