A 38 gram sample of a substance that is used to sterilize surgical instruments has a k-value of 0.113. Find the substance's half-life in days, round to the nearest tenth.

Answers

Answer 1

Answer:

6.13 days

Step-by-step explanation:

Hello,

This question directly relates to radioactivity of a substance.

Data,

k = 0.113

Initial mass (No) = 38g

Half life of the substance (T½) = ?

To solve this question, we don't need the value of the initial mass because the variables in half life (T½) formula does not require it.

T½ = ln2 / k

Note : ln2 is a constant derived while k is the decay constant of the substance

T½ = 0.693 / 0.113

T½ = 6.13 days

The half life of the substance is 6.13 days


Related Questions

Solve for x 3x - 5 = 2x + 6.
01
O-1
O 11
0-11

Answers

Answer:

X= 11

Step-by-step explanation:

Move constant to the right side and change its sign

If
x = 3,
y = -5 and z-7, find
x +yz +xyz.

Answers

Answer:

143

Step-by-step explanation:

Since the values of x y and z are given

Substitute the value in the polynomial, so it'll become,

x+yz+xyz

= (3)+(-5)*(-7)+(3)*(-5)*(-7)

= 3+35+(3)*(-7)*(-5)

{Two negatives when multiplied becomes positive}

=3+35+3*35

= 3+35+105

=143

In a grade 11 class, 40% of the students are taking Geography, 30% are taking History and 10% are taking both. If 40 students are enrolled in the grade 11 class, how many students are taking neither Geography or History?

Answers

I put the wrong answer

b2 - 7b + 12 = 0
Factored equation: ( ) ( ) = 0
ANSWERS: b = ____, and b = ____

Answers

b2-7b+12=0
(b-3)(b-4)=0
b= 3 or 4

Answer: (b - 4)(b - 3); b = 4 and 3

Step-by-step explanation:

ima assume these are exponents since you didnt care to correctly write the equation.

What two numbers multiply to equal 12, but add to equal -7? That's -4 and -3

So the factored form of this trinomial is (b - 4)(b - 3) = 0. Make each of these expressions equal to 0 in order to get your answer.

Here are seven tiles Tom takes a tile at random. He does not replace the tile. Tom then takes at random a second tile. a) Calculate the probability that both tiles Tom takes have the number 1 on them. b) Calculate the probability that the number on the second tile Tom takes is greater than the number on the first tile he takes.

Answers

Answer:

a) 1/21

b) 8/21

Complete question:

There are seven tiles:

1,1,3,3,3,5,5

Tom takes a tile at random. He does NOT replace the tile.

Tom then takes another tile at random.

a) Calculate the probability that both tiles Tom takes have the number 1 on them. b) Calculate the probability that the number on the second tile Tom takes is greater than the number on the first tile he takes.

Step-by-step explanation:

Total number of tiles = 7

Let Probability of having number 1 on the tiles = Pr (having 1)

Pr (having 1) = (number of times 1 appears on tiles)/(total number of tiles)

Number of times 1 appears on tiles = 2

Pr (having 1) = 2/7

Two tiles are drawn without replacement:

Probability of both tiles having number 1 on them = Pr (having 1 for both 1st and 2nd time)

= Pr (having 1) × Pr (having 1)

Since it is without replacement, the numbers in the second pick would reduce by 1 in both the numerator and denominator since we are picking same number. That is from 7 to 6 and from 2 to 1 to reflect that it was replaced.

= 2/7 × 1/6

= 2/42

Probability of both tiles having number 1 on them = 1/21

b) If 1st tile = 1, the second tile could be = 3 or 5

The pairs = Pr(1 and 3) and Pr(1 and 5)

Where Pr = probability

The probability is still without replacement. For both probability, the numbers in the second pick would reduce by 1 in the denominator since we are picking different numbers. That is from 7 to 6

Number of times 3 appears on tiles = 3

Number of times 5 appears on tiles = 2

Pr(1 and 3) = (2/7 × 3/6) = 1/7

Pr(1 and 5) = (2/7 × 2/6) = 2/21

If 1st tile = 3, the second tile = 5

Pr(3 and 5) = (3/7 × 2/6) = 1/7

If 1st tile = 5, the second tile = 0 (no number is greater than 5

Pr(5 and 0) = 0

Probability that the number on the second tile Tom takes is greater than the number on the first tile he takes = Pr(1 and 3) + Pr(1 and 5) + Pr(3 and 5) + Pr(5 and 0)

= 1/7 + 2/21 + 1/7 + 0

= (3+2+3)/21 = 8/21

Probability that the number on the second tile Tom takes is greater than the number on the first tile he takes = 8/21

Find the surface area.​

Answers

Well i am not sure
The answer is c
Answer is C

Find the area of the triangle to get 72cm^2. There are two triangles so times 72 by 2 to get 144

Find the area of the first side by doing 12 x 30 = 360cm^2

Find the area of the second side by doing 9 x 30 = 270cm^2

Find the area of the base by doing 18 x 30 = 540cm^2

Add 144+360+270+540 = 1314cm^2

Mitchell's family is slow cooking 2 3/4 pounds of meat. The recipe says to cook the meat 1 1/2 nours per pound,
How long should Mitchell's family cook the meat?
A 1 5/6
B. 2 3/8
C 4 1/ 8
D. 4 1/4​

Answers

Answer:

C

Step-by-step explanation:

Multiply the 1.5 hours per pound by 2.75 pounds and we get 4.125 hours or    4 1/8

Answer:

C: 4 1/8

Step-by-step explanation:

i took the quiz

Answer each question and explain your reasoning.
How long is 75% of 60 minutes?​

Answers

Answer:

45 minutes

Step-by-step explanation:

75% is the same as [tex]\frac{3}{4}[/tex]. This means that we can multiply 60 by  [tex]\frac{3}{4}[/tex] to find 75% of 60.

[tex]60*\frac{3}{4} \\\\\frac{180}{4} \\\\\frac{90}{2}\\\\45[/tex]

Answer:

45 minutes

Step-by-step explanation:

Of means multiply

75% * 60

Change to a decimal

.75 * 60

45

45 minutes

Find the simplest pattern and fill in the missing number. 45, 30, 18, 9, ... 0

Answers

Answer:

3 the patten is the previous subtracted about decrease by 3

Step-by-step explanation: the pattern decrease the number subtracted by 3 so it starts with 15 and goes to 12 then to 9 so the last one would be six and 9 - 6 = 3

if f(x) = 2x+1/x-4 what is the value of f^-1(3)

Answers

Answer:

f^-1(3) = 1.719 or  f^-1(3) = 0.149

Step-by-step explanation:

for inverse function x and y coordinates are flipping so graph the function and find for what x - coordinate y- coordinate = 3

in case that f(x) = [tex]2x + \frac{1}{x-4}[/tex] than f^-1(3) = 1.719

in case that f(x) = [tex]2x + \frac{1}{x} -4[/tex] than f^-1(3) = 0.149

Answer: B

B (19/11) when divided = 1.72 repeat

of all the options given, this is the closest to the above answer.

Find the perimeter of a rectangle whose length is (4a+b)cm and width (a+6)cm​

Answers

Answer:

P = 10a +2b+12

Step-by-step explanation:

P = 2 (l+w) for a rectangle

P = 2 ( 4a+b + a+6)

Combine like terms

P = 2(5a+b+6)

Distribute

P = 10a +2b+12

Answer:

Given below

Hope it helps

Step-by-step explanation:

Perimeter= 2(l+b)

= 2(4a+b+a+6)

= 2(5a+b+6)

= 10a+2b+12 cm^2

How many cubes eith side lengths of 1/4 cm does it take to fill the prism? Please help

Answers

Step-by-step explanation:

In order to find Volume for a rectangle use the formula: L * W * H

2 1/4 * 3/4 * 1 1/4 = 2 7/64

A cube with the side lengths of 1/4:   1/4 * 1/4 * 1/4 = 1/64

Divide 1/64, by the prisms volume, 2 7/64 to get 135.

I'm not sure if this is right, but I hope that helps! :)

Scheels received a shipment of 400 water bottles. 30% were yellow.

How many yellow water bottles were in the shipment?

Answers

Answer:
There were 120 yellow water bottles in the shipment

Explanation:
Multiply 400 by 30% to find out how many water bottles came in yellow.

400 • .30 = 120

So, 120 were yellow.

_________________________________

Solution,

30% of 400

= 30/100*400

=120

120 yellow water bottles were in the shipment.

Hope it helps

Good luck on your assignment

__________________________________

4x2 + 25y2
factor the following

Answers

Answer:

see explanation

Step-by-step explanation:

This polynomial is irreducible, that is cannot be factored.

4x² + 25y² ← is a prime polynomial

Answer:

1, the polynomial itself

Step-by-step explanation:

This is a prime polynomial since the terms have no common factor. The only factors it has are 1 and 4x2+25y2 (the number itself)

A closed box has a square base with side length feet and height feet given that the volume of the box is 34 ft.³ express the surface area of the box in terms of length only

Answers

Answer:

[tex]\dfrac{2s^3+136}{s}[/tex]

Step-by-step explanation:

Let the side length of the square base =s feet

Let the height of the box = h

Given that the volume of the box = [tex]34$ ft^3[/tex]

Volume of the box =[tex]s^2h[/tex]

Then:

[tex]s^2h=34$ ft^3\\$Divide both sides by s^2\\h=\dfrac{34}{s^2}[/tex]

Surface Area of a Rectangular Prism =2(lb+bh+lh)

Since we have a square base, l=b=s feet

Therefore:

Surface Area of our closed box[tex]= 2(s^2+sh+sh)[/tex]

[tex]S$urface Area= 2s^2+4sh\\Recall: h=\dfrac{34}{s^2}\\$Surface Area= 2s^2+4s\left(\dfrac{34}{s^2}\right)\\=2s^2+\dfrac{136}{s}\\$Surface Area in terms of length only=\dfrac{2s^3+136}{s}[/tex]

ANSWER THIS AND I WILL FRIEND YOU!!! What is x? 2x(3+4x) *2 -5

Answers

Answer:

Step-by-step explanation:

[tex]2*(3+4x) *2 -5\\6+8x*2-5\\16x =-6-5\\16x = -11\\x = 11/16[/tex]

Let $z$ and $w$ be complex numbers satisfying $|z| = 4$ and $|w| = 2$. Then enter in the numbers\[|z+w|^2, |zw|^2, |z-w|^2, \left| \dfrac{z}{w} \right|^2 \]below, in the order listed above. If any of these cannot be uniquely determined from the information given, enter in a question mark.

Answers

Answer:

a) |z+w|² cannot be uniquely determined from the information provided.

b) |zw|² = [|z| × |w|]² = (4×2)² = 64.

c) |z+w|² cannot be uniquely determined from the information provided.

d) |z/w|² = [|z|/|w|]² = (4/2)² = 4

Step-by-step explanation:

z & w are complex numbers with magnitudes

|z| = 4

|w| = 2

We are the told to find

|z + w|²

|zw|²

|z - w|²

|z/w|²

Let the complex numbers be

z = x + iy

w = a + ib

|z| = √(x² + y²) = 4

|w| = √(a² + b²) = 2

|z|² = x² + y² = 16

|w|² = a² + b² = 4

z+w = (x + iy) + (a + ib) = (x + a) + i(y + b)

|z+w|² = (x + a)² + (y + b)² = x² + 2ax + a² + y² + 2by + b²

= (a² + b²) + (x² + y²) + 2ax + 2by

= |w|² + |z|² + 2ax + 2by

= 4 + 16 + 2ax + 2by

= 20 + 2(ax + by)

This cannot be determined from the information provided.

zw = (x + iy)(a + ib) = ax + i(bx + ay) - by

= (ax - by) + i(bx + ay)

|zw|² = a²x² + b²y² - 2abxy + b²x² + a²y² + 2abxy

= a²x² + b²y² + b²x² + a²y²

= a²(x² + y²) + b²(x² + y²)

= (a² + b²)(x² + y²)

= |w|² × |z|²

= 4×16

= 64

c) z-w = (x + iy) - (a + ib) = (x - a) + i(y - b)

|z-w|² = (x - a)² + (y - b)²

= x² - 2ax + a² + y² - 2by + b²

= (a² + b²) + (x² + y²) - 2ax - 2by

= |w|² + |z|² - 2ax - 2by

= 4 + 16 - 2ax - 2by

= 20 + 2(ax + by)

This cannot be determined from the information provided.

d) z/w = (x + iy)/(a + ib)

Rationalizing by multiplying numerator and denominator by (a - ib)

(z/w)= [(x + iy)(a - ib)/(a + ib)/(a - ib)]

= [ax - by + i(ay - bx)]/(a² + b²)

|z/w|² = [(ax + by)² + (ay - bx)²]/(a² + b²)²

= [a²x² + b²y² + 2abxy + b²x² + a²y² - 2abxy]/(a⁴ + b⁴ + 2a²b²)

= [a²x² + b²y² + b²x² + a²y²]/[(a² + b²)² - 2a²b² + 2a²b²]

= [(a² + b²)(x² + y²)]/[(a² + b²)²]

= [(x² + y²)/(a² + b²)]

= |z|²/|w|²

= (4/2)²

= 4

Hope this Helps!!!

The lengths of a lawn mower part are approximately normally distributed with a given mean Mu = 4 in. and standard deviation Sigma = 0.2 in. What percentage of the parts will have lengths between 3.8 in. and 4.2 in.? 34% 68% 95% 99.7%

Answers

Answer:

b) 68%

The percentage of the parts will have lengths between 3.8 in. and 4.2 in

P( 3.8 ≤ x ≤ 4.2) = 0.6826 = 68 %

Step-by-step explanation:

Let 'X' be the normally distributed

mean 'μ'= 4 inches

standard deviation 'σ' = 0.2 inches

Case(i):-

when x₁ = 3.8 inches

[tex]Z_{1} = \frac{x_{1}-mean }{S.D} = \frac{3.8-4}{0.2} = -1[/tex]

Case(ii):-

when  x₂= 3.8 inches

[tex]Z_{2} = \frac{x_{2}-mean }{S.D} = \frac{4.2-4}{0.2} = 1[/tex]

The probability of the parts will have lengths between 3.8 in and 4.2 in

[tex]P( 3.8\leq x\leq 4.2) = P(-1\leq z\leq 1)[/tex]

                        = P(Z≤1) - P(Z≤-1)

                        =  0.5 +A(1) -(0.5-A(1)

                       = 2 A(1)

                       = 2×0.3413

                      = 0.6826

Conclusion:-

The percentage of the parts will have lengths between 3.8 in. and 4.2 in

P( 3.8 ≤ x ≤ 4.2) = 0.6826 = 68 %

Answer:

B

Step-by-step explanation:

E2020

The height, h in feet, a ball with reach when thrown in the ais is a function of time, t, in seconds,given by the equation h(t)=-16t2+35t+10. Find, to the nearest tenth, the maximum height, in feet, the ball will reach. The time when it reached its maximum height. How many seconds after the ball is thrown it will hit the ground?

Answers

Answer:

The maximum height the ball will reach is 29,141 feet.

The time when it reached its maximum height is 1.094 seconds.

2,443 seconds after throwing the ball, it will touch the ground.

Step-by-step explanation:

The function h (t) = - 16t² + 35t + 10 is a quadratic function of the form f (x) = ax² + bx + c, where a = -16, b = 35 and c = 10. To calculate the maximum height, you must then find the maximum of the function. In other words, Quadratic functions have a maximum (if a <0) or a minimum (if a> 0). This point is the vertex of the parabola.

The vertex coordinate on the x axis can be calculated by:

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

The value of the vertex on the y axis is obtained by substituting the value of "x vertex" in the function f (x), that is, by calculating f ([tex]\frac{-b}{2*a}[/tex]).

In this case, where h ([tex]\frac{-b}{2*a}[/tex]) is the maximum height:

[tex]t=\frac{-b}{2*a}=\frac{-35}{2*(-16)} =1.09375[/tex]≅ 1.094 seconds

So: h(1.094)= -16*1.094² + 35*1.094 + 10

h(1.094)=29.151

The maximum height the ball will reach is 29,141 feet.

The time when it reached its maximum height is 1.094 seconds.

To calculate the number of seconds after the ball is thrown it will hit the ground, you must calculate the roots of the quadratic function. For this you must apply:

[tex]x1,x2=\frac{-b+-\sqrt{b^{2}-4*a*c } }{2*a}[/tex]  

where x1, x2 are the two roots of the function f(x)=a*x² +b*x + c

In this case:

[tex]t1,t2=\frac{-35+-\sqrt{35^{2}-4*(-16)*10 } }{2*(-16)}[/tex]

Solving, you get t1=-0.256 and t2=2.443

Since the time cannot be negative, 2,443 seconds after throwing the ball, it will touch the ground.

Please answer correctly !!!!!!! Will mark brainliest !!!!!!!!!!!!

Answers

Answer:

f⁻¹(-2)=3

f⁻¹(1)=0

Step-by-step explanation:

inverse function flips x any coordinate into y and x

Which is the value of this expression when p=-2 and q=-1?

A. -4

B. -1/16

C. 1/16

D. 4

Answers

Answer:

D. 4

Step-by-step explanation:

[tex] [(p^2) (q^{-3}) ]^{-2}.[(p)^{-3}(q)^5] ^{-2}\\\\

=[(p^2) (q^{-3}) \times(p)^{-3}(q)^5 ]^{-2}\\\\

=[(p^{2}) \times(p)^{-3} \times (q^{-3}) \times(q)^5 ]^{-2}\\\\

=[(p^{2-3}) \times (q^{5-3}) ]^{-2}\\\\

=[(p^{-1}) \times (q^{2}) ]^{-2}\\\\

=(p^{-1\times (-2)}) \times (q^{2\times (-2) }) \\\\

=p^{2}\times q^{-4} \\\\

= \frac{p^2}{q^4}\\\\

= \frac{(-2)^2}{(-1)^4}\\\\

= \frac{4}{1}\\\\

= 4[/tex]

Can you please help me

Answers

Answer:

complementary angle: 63

supplementary angle: 153

Step-by-step explanation:

Complementary angles mean angles that add up to 90.  Therefore 90-27=63

Supplementary angles are angles that add up to 180. Therefore 180-27=153

What is the solution to the following equation? 4(3x − 11) + 23 = 5x − 14 a 0 b 1 c 10 d 14

Answers

Answer:

b 1

Step-by-step explanation:

√10·√8 is this equal to the √80?

Answers

Answer: yes

Step-by-step explanation:

They are both equal to 4/5

What is a real life example for an integer

Answers

Answer:

Some examples of integers are -1, 0, and 1.

the area that lies between Z= - 0.42 and Z= 0.42 is

Answers

Answer:

the answer is 0.84

Step-by-step explanation:

assume the two numbers are on a number line and take the absolute value of their difference

The answer is 0.84 assume that the two numbers are on a number line

let f be defined as follows f(x)=4x find f^-1(x)

Answers

Answer:

So this is the inverse function

Please say ---- solve for the inverse f(x)

instead of  ---- solve for f^-1(x)

x/4 division is the opposite of multiplication

so instead of multiplying by 4 we divide by 4

:)

Thanks for the question, Im working up to get a brainly answer and Master Answerer.

:)

Step-by-step explanation:

In how many ways can you
select a group of 6 friends to
invite over from a group of
22 friends?

Answers

Answer:74613

Step-by-step explanation:

n!/r!(n-r)!

22!/6!(22-6)!

=74613

What’s the answer ??? Help

Answers

Answer:

It's B. (2x+5) (x+4)

Answer:

b

Step-by-step explanation:

2x²+13x+20

You can just try all the answers if you'd like and see which one equals 2x²+13x+20.

Using FOIL for all of them:

a. (2x-5)(x-4) = 2x²-8x-5x+20 = 2x²-13x+20

b. (2x+5)(x+4) = 2x²+8x+5x+20 = 2x²+13x+20

c. (2x+2)(x+10) = 2x²+20x+2x+20 = 2x²+22x+20

d. is obviously not correct since we already have an answer.

Our answer is b. (2x+5)(x+4)

Find the sum of the first 44 terms of the following series, to the nearest integer. 10, 14,18,...

Answers

Answer:

4224

Step-by-step explanation:

Here, we want to calculate the sum of the first 44 digits

Term a which is first digit is 10

common difference which is difference of terms = 14-10 = 18-14 = 4

Now the nth term of an arithmetic sequence is

a + (n-1)d

44th term means n = 44

10 + (44-1)4

10 + 43(4)

10 + 172 = 182

To find the sum, we use the formula

Sn = n/2[a + L]

where a is the first term and L is the 44th term

Sn = 44/2 (10 + 182)

Sn = 22(192)

Sn = 4,224

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Which of the following polygons can form a regular tessellation? The table shows ordered pairs of the function y = 16 + 0.5x .A 2-column table with 6 rows. The first column is labeled x with entries negative 4, negative 2, 0, 1, x, 10. The second column is labeled y with entries 14, 15, 16, 16.5, y, 21.Which ordered pair could be the missing values represented by (x, y)?(0, 18)(5, 19.5)(8, 20)(10, 21.5) posted by accident my bad.................................................. From a barrel of colored marbles, you randomly select 1 blue, 2 yellow, 7 red, 6 green, and 2 purple marbles. Find the experimental probability of randomly selecting a marble that is NOT yellow.A: 8/9B: 9/10C: 11/18D: 7/9 2/ 7 2/15 = ____ solve ? What is the domain of the function shown on the graph? Which cosine function has maximum of 0.5, a minimum of -0.5, and a period of 2(pi)/3 Read this passage."Have you ever left your computer feeling sore in your wrists or shoulders? Or does your neck feel strained from looking up or down at your monitor? Take amoment next time you are at your workstation to see what your setup looks like. Ergonomics is the practice of designing and arranging objects to allow forefficiency and healthy alignment of the body while performing tasks. By doing a little research about an ergonomic workstation and then making small changes toyour work area, you can prevent muscle strains and tension, headaches, pinched nerves, and other physical disorders. For example, raise or lower your chair soyour feet can touch the ground and so it is at the proper height and distance from your keyboard and mouse. Also, you might need to prop your monitor on a sturdyplatform to make the screen in line with your eyes so you do not have to lift or lower your head to see properly. Changes like these may seem small, but having anergonomic workstation just might save you a trip to the doctor."Which supporting detail best supports the main idea? The ad promotes a new brand of car. What benefit of the internal combustion engine does the ad emphasize? As a member of the Game Shop rewards program, you get a 12% discount on purchases. All sales are subject to an 8% sales tax. Write functions to model the discount and the sales tax, then identify the rule for the composition function that calculates the final price you pay Games Shop. help please! our existing body of scientific knowledge was developed Can someone please help me I am almost done with this Why is integrity so important? 10 POINTS AND BRAINLIST PLSSS MY GRADE IS ON THE LINE!!!!!!!!!!!Read the excerpt below, then answer the question. The Tinker's Willow Edward W. Frentz One day, when my Grandfather Gifford was about seven years old, he looked across the road to his father's blacksmith shop, and seeing someone sitting on the bench by the door, went over to learn who it was. He found a little old man, with thick, bushy eyebrows and bright blue eyes. His clothes were made all of leather, which creaked and rattled when he moved. By his side was a partly open pack, in which grandfather could see curious tools and sheets of shiny tin. By that he knew that the man was the traveling tinker, who came once or twice a year to mend leaky pans and pails, and of whom he had heard his mother speak. The old man was eating his luncheon - a slice or two of bread, a bit of cold meat, and a cold potato; and because it seemed so poor a luncheon, grandfather went back to the house and brought two big apples from the cellar. The old man thanked him and ate the apples. Then he got up, brushed the bread crumbs from his leather breeches, and taking a little tin dipper from his pack, went down to the brook for a drink of water. When he had had his fill, he came back to the bench and sat down. Which of the following describes the place in this excerpt? a small town, outside a blacksmith shop in a blacksmith shop a big city a brook A scientist is tracking object orbiting the sun that is found between Mars and Jupiter which additional feature can be used to determine the object is an astroid What is the slope of a line that is perpendicular to 6x + 3y = -9?A 2B. 1wC. -2D.Ninh1Please select the best answer from the choices provided write and learn a letter to a cousin to borrow a book find the value of A when pi= 3.142 and r= 5 Discipline, Integrity, Compassion, Courage and Humility. Please describe how you have demonstrated these core values in your personal and academic endeavors. Your discussion should highlight how you were an exemplary JRF Scholar and how your future career goals will embody these values? how did Germany invade france