A 10 gram sample of a substance that’s used to detect explosives has a k-value of 0.1356.Find the substances half life in days.Round your answer to the nearest tenth.

Answers

Answer 1

Answer:

t ≈ 5.1 days

Step-by-step explanation:

A 10 gram sample of a substance thats used to detect explosives has a k-value of 0.1356. Find the substances half-life in days. round your answer to the nearest tenth. N=N₀ e^-kt N₀= initial mass (at time t = 0) N = mass at time t k= a positive constant that depends on the substance itself and on the units used to measure time t=time in days

The initial condition is that, at time t = 0, the amount of substance contains originally 10 grams

Find the value of N₀

N=N₀ e^-kt

We substitute:

10 = N₀ {e^(-0.1356)*0}

10 = N₀ (e^0)

10=N₀(1)

10=N₀

N₀ = 10

When the substance is in half-life

That is, half of the original substance (5 grams)

Find t

N=N₀ e^-kt

5 = 10 e^(-0.1356*t)

0.5 = e^(-0.1356*t)

Bring down t by multiplying natural log on both sides

ln(0.5) = -0.1356*t

Divide both sides by -0.1356

t = -(ln(0.5) / 0.1356

t ≈ 5.11 days

To the nearest tenth

t ≈ 5.1 days

Answer 2

Answer:

5.1 days in Plato

Step-by-step explanation:


Related Questions

Need to find the Domain and Range

Answers

Answer:

D: {x∈R | -2 ≤ x ≤ 2 }

R: {y∈R | 0 ≤ y ≤ 4 }

Step-by-step explanation:

The domain ranges between -2 and 2

The range ranges between 0 and 4

Solve the triangle. A = 51°, b = 14, c = 6 A. a ≈ 14.9, C ≈ 28.1, B ≈ 100.9 B. a ≈ 11.2, C ≈ 24.1, B ≈ 104.9 C. a ≈ 14.9, C ≈ 24.1, B ≈ 104.9

Answers

Answer:

(B) has the closest values.

Step-by-step explanation:

Solve the triangle: A = 51°, b = 14, c = 6

A. a ≈ 14.9, C ≈ 28.1, B ≈ 100.9

B. a ≈ 11.2, C ≈ 24.1, B ≈ 104.9

C. a ≈ 14.9, C ≈ 24.1, B ≈ 104.9

Using the cosine rule,

a^2 = b^2+c^2-2bc (cos(A))

= 196+36 - 2(14)(6)cos(51)

=  196+36 - 105.72

= 126.27

a = sqrt(126.27)

= 11.24

using sine rule,

sin(C)/sin(A) = 6/11.24

sin(C) = 6/11.24*sin(51)= 0.41495

C = arcsin(0.41495 = 24.5 degrees, reasonably close to the given value, probably due to the answer used the rounded value of a.

B = 180-51-24.5 =104.5

Out of the given options, only (B) has the correct value of a and C

An air traffic controller spots two airplanes at the same altitude converging to a point as they fly at right angles to each other. One airplane is 150 miles from the point and has a speed of 300 miles per hour. The other is 200 miles from the point and has a speed of 400 miles per hour.(a) At what rate is the distances between the planes decreasing?(b) How much time does the air traffic controller have to get one of the planes on a different flight path?

Answers

Answer:

The answer to this question can be defined as follows:

In option A, the answer is "- 357.14 miles per hour".  

In option B, the answer is "-0.98".

Step-by-step explanation:

Given:

[tex]\frac{dx}{dt} =- 300 \text{ miles per hour}[/tex]

[tex]\frac{dy}{dt} =- 400 \text{ miles per hour}[/tex]

find:

[tex]\frac{ds}{dt} =?[/tex] when

[tex]x= 150 \\y= 200\\s=x+y\\\\[/tex]

  [tex]= 150+200 \\\\=350[/tex]

[tex]\to s^2=x^2+y^2\\[/tex]

differentiate the above value:

[tex]\to 2s\frac{ds}{dt}= 2x \frac{dx}{dt}+2y \frac{dy}{dt}[/tex]

[tex]\to 2s\frac{ds}{dt}= 2(x \frac{dx}{dt}+y \frac{dy}{dt})\\\\\to \frac{ds}{dt}= \frac{(x \frac{dx}{dt}+y \frac{dy}{dt})}{s}\\\\[/tex]

        [tex]= \frac{(150 \times -300 +200 \times -400 )}{350}\\\\= \frac{-45000+ (-80000) }{350}\\\\= \frac{- 125000 }{350}\\\\= - 357.14 \ \text{miles per hour}[/tex]

In option B:

[tex]\to d=rt\\\\ \to t= \frac{d}{r}[/tex]

[tex]\to \ \ d= 350 \ \ \ \ \ \ r= -357.14\\[/tex]

[tex]\to t= - \frac{350}{357.14}\\\\\to t= - 0.98[/tex]

PLS HELP I WILL GIVE YOU A BRAINLIST AND A THANK YOU!!!!

Answers

Answer:

75

Step-by-step explanation:

We have a 90 degree angle and a 15 degree angle that add up to 105. The angle that is missing can be found by doing 180 - 105 = 75 (since it's a straight line). X is vertical from the 75 degree angle, so 75 is your answer.

Answer:

x= 75°

Step-by-step explanation:

i have added a sketch of it

A classroom has 14 boys and 18 girls. What is the ratio of boys to girls?

Answers

Answer:

7:9

Step-by-step explanation:

boys:girls

14:18

simplify -- divide by 2

7:9

Answer:

7:9

Step-by-step explanation:

so we start of with 14 boys to 18 girls, but we need to simplify it.

so we half both numbers to get to 7:9.

this is the most simplified form of this ratio.

the answer is 7:9

Let's see what it would take to win that trip to Hawaii.
Remember that you think you'll respond to 12 questions and hope to score 600 points to win,
although it's possible to score even more points or many fewer (including negative scores!) on
the show.
Here are the equations you wrote to model your winning scenario:
x+y=12
100x - 200y = 600
Are the boundaries of the first equation viable in the second equation? What does this
suggest about your plan to score 600 points?
Select the two correct statements.​

Answers

Answer:

A and D choices (Plato)

Step-by-step explanation:

The upper boundary of the first equation is at x = 12, y = 0. With these values, this is the second equation:

100(12) − 200(0) = 1,200.

The lower boundary of the first equation is at x = 0, y = 12. With these values, this is the second equation:

100(0) − 200(12) = -2,400.

Both of these scores are possible in the game, so they are both viable.

Because the upper boundary is greater than 600, it suggests that you can still score 600 points and win the game even if you get one or two of the questions incorrect.

In fact, you could give 10 correct and 2 incorrect answers to score 600 points and still beat the champion, Kimberly, assuming she answers 15 correct and 5 incorrect to score 500 points.

Please explain and help

Answers

Answer:

y=-x+2  

Step-by-step explanation:

it is linear equation y=mx+b two points (0,2),(1,1)

find m ( slope)=y2-y1/x2-x1 ⇒1-2/1-0⇒-1

y=mx+b choosea point from graph :(0,2)\when x =0 the y=b=2

y=-x+2  

One hundred people, ages 11-15, were randomly surveyed to find their opinion of their favorite leisure time activity. Sixty-four percent of them said they liked to spend time watching TV. If there are 1500 students in your school, about how many of them would you predict would enjoy watching t.v. A.2343 B.960 C.640 D.500

Answers

Answer:

If there are 1500 students in your school then 960 students would enjoy watching TV

Step-by-step explanation:

Step 1: We know that 64% of kids aged from 11 to 15 enjoy watching TV and there is 1500 students in your school

Step 2: We now want to find 64% of 1500, we can rewrite 64% as 0.64. We multiple 1500 by 0.64 to find out how many students enjoy watching TV

0.64 x 1500 = # of students who like watching TV

960 = # of students who like watching TV

Therefore out of 1500 students, 960 would enjoy watching TV

Given an angle of a triangle and the opposite side length; which trigonometric function would you use to find the hypotenuse? a TAN b COS c SIN d Not enough information

Answers

Answer:

Sin

Step-by-step explanation:

Sin < = opposite/hypotenuse

PLEASE help me with this question! No nonsense answers please. This is really urgent.

Answers

Answer:

A) 15.6 ft²

Step-by-step explanation:

Area of the circle

A=[tex]\pi[/tex]r²

A=[tex]\pi[/tex](5.7)²

A=102.07

Area of the segment

102.07*55/360

15.594

really urgent...i need the working also ...pls help me​

Answers

Answer:

See below.

Step-by-step explanation:

In each case, you are looking for time. We know speed is distance divided by time. Lets start with the speed formula.

speed = distance/time

Now we solve it for time. Multiply both sides  by time and divide both sides by speed.

speed * time = distance

time = distance/speed

Time is distance divided by speed. In each problem, you have a speed and a distance. Divide the distance by the speed to to find the time.

1) speed = 44.1 km/h; distance = 150 km

time = distance/speed = 150 km/(44.1 km/h) =

= 3.401 hours = 3 hours + 0.401 hour * 60 min/hour = 3 hours 24 minutes

2) speed = 120 km/h; distance = 90 km

time = distance/speed = 90 km/(120 km/h) =

= 0.75 hours = 0.75 hour * 60 min/hour = 45 minutes

3) speed = 125 m/s; distance = 500 m

time = distance/speed = 500 m/(125 m/s) =

= 4 seconds

if one square yard of carpet costs $15.40, how much will 45.5 square yards cost? ( value only, no commas, dollar signs, symbols, or units)

Answers

Answer: 700.70 dollars

Work Shown:

1 square yard = 15.40 dollars

45.5*1 square yard = 45.5*15.40 dollars

45.5 square yards = 700.70 dollars

In the second step, I multiplied both sides by 45.5 to turn the "1 square yard" into "45.5" square yards.

the sum of 35 and one fifth part of itself is added to the sum of one seventh of 11 and 8​

Answers

Answer:

313/7

Step-by-step explanation:

Here, we are interested in turning the wordings of the statement to numeric values.

We take it one at a time.

Sum of 35 and 1/5(35) = 35 + 7 = 42

This is added to 1/7(11 + 8)

= 1/7(19) = 19/7

So we have;

42 + 19/7 = (294 + 19)/7 = 313/7

Write each expression using a positive exponent. ("/" means division)("^" means to the power of) 9^-4

Answers

Answer:

[tex]\frac{1}{9^4}[/tex].

Step-by-step explanation:

[tex]9^{-4}[/tex]

= [tex]\frac{1}{9^4}[/tex]

= [tex]\frac{1}{9 * 9 * 9 * 9}[/tex]

= [tex]\frac{1}{81 * 81}[/tex]

= [tex]\frac{1}{6561}[/tex]

= 0.0001524157903.

Hope this helps!

need help...!!ASAP..!! plz....

Answers

the answer for this is A

Answer:

Correct option is A

Step-by-step explanation:

3x - 7

Three times a number x minus 7

Or

The difference of there times a number and 7

The following expression is a polynomial: 4x + 5y True False

Answers

Answer: False. This expression is a monomial!

Answer:

false

Step-by-step explanation:

it is molonomial

According to data from the U.S. Department of Education, the average cost y of tuition and fees at public four-year institutions in year x is approximated by the equation where x = 0 corresponds to 1990. If this model continues to be accurate, during what year will tuition and fees reach $4000?

Answers

Answer:

Graphing Calculator

Step-by-step explanation:

Solve for x 3(x+7)-14=22

Answers

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Hi my lil bunny!

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Let's solve your equation step-by-step.

[tex]3(x+7)-14=22[/tex]

Step 1: Simplify both sides of the equation.

[tex]3 ( x + 7 ) - 14 = 22\\(3)^(x) + (3) (7) + - 14 = 22[/tex] (Distribute)

[tex]3x + 21 + -14 = 22[/tex]

[tex]( 3x) + (21 + -14 ) = 22[/tex] (Combine Like Terms)

[tex]3x + 7 = 22\\3x + 7 = 22[/tex]

Step 2: Subtract 7 from both sides.

[tex]3x + 7 - 7 = 22 - 7 \\3x = 15[/tex]

Step 3: Divide both sides by 3.

[tex]\frac{3x}{3} = \frac{15}{3} \\x = 5[/tex]

So your answer would be : [tex]\boxed {x = 5}[/tex]

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Have a great day/night!

❀*May*❀

ux=x+y/k, solve for x

Answers

Answer:

x = y/( ku-1)

Step-by-step explanation:

Here in this question, we are asked to solve for x.

we have;

Ux = x+ u/ k

cross multiply;

k * Ux = x + y

kUx = x + y

kUx- x = y

x(KU-1) = y

x = y/( ku-1)

40. Which families of plane figures given below are NOT always similar?
A. Squares
C. Equilateral triangles
B. Circles
D. rectangle​

Answers

Answer:

Rectangle

Explanation:

Rectangles can be oblong, and square is also a rectangle.

PLZ HELP!!!! ASAP !!!!

Answers

Answer:

(A)

Sin á = a/c

Cos ∅ = a/c

Tan á = a/b

(B)

Sin á = a/c

Cos á = b/c

Tan á = a/b

Therefore á=

(inverse sin) a/c

Or

(Inverse cos) b/c

Or

(Inverse tan) a/b

(C)

If b = 12 and c = 13

then a =√(c²-b²)

= 5

Hence 5/13 = a/c

Therefore sin á = cos ∅ = a/c = 5/13

What the answer question

Answers

Answer:

Surface area = 373.66Step-by-step explanation:

[tex]T.S.A = \pi r(r+l)\\l = 10mm\\r = 7mm\\\\T.S.A = 3.14 \times 7(7 + 10)\\= 21.98(17)\\T.S.A = 373.66\\\\T.S.A = 373.66[/tex]

A cylinder has a radius of 2.8 in and a height of 2.4 in. Which cylinder is similar?
(p.s. the pic is the awnser choices)

also if you can awnser this xan you awnser it asap im currently taking a test thanks :)​

Answers

Answer:

option 2 with radius of 1.4 in, and height of 1.2 in.

Step-by-step explanation:

If two cylinders are similar, the ratio of one cylinder's radius to its height must be the same as that of the other.

To know which cylinder is similar to the given cylinder with radius 2.8 in and height of 2.4 in, find the ratio, and compare with the ratio of the options provided. The option with the same ratio, is the cylinder that is similar.

This,

The given cylinder => radius : height = [tex] \frac{2.8}{2.4} = \frac{0.7}{0.6} = \frac{7}{6} [/tex]

First option:

Radius : height = [tex] \frac{1.8}{1.4} = \frac{0.9}{0.7} = \frac{9}{7} [/tex]

Second option:

Radius : height = [tex] \frac{1.4}{1.2} = \frac{0.7}{0.6} = \frac{7}{6} [/tex]

Third option:

Radius : height = [tex]\frac{5.6}{4.2} = \frac{0.8}{0.6} = \frac{0.4}{0.3} = \frac{4}{3}[/tex]

Fourth option:

Radius : height = [tex] \frac{2.4}{2.8} = \frac{0.6}{0.7} = \frac{6}{7} [/tex]

The correct option with the cylinder that is similar with the given cylinder is option 2 with radius of 1.4 in, and height of 1.2 in.

Triangle A' B' C' is a dilation of a triangle ABC. The scale factor is [tex]\frac{3}{4}[/tex]. Point B is 11 inches away from the center of dilation is point B'?

Answers

Answer:

None of the options are correct

Step-by-step explanation:

Let us assume point B is at (x, y) and the center of dilation is at (a, b). Therefore the distance between the two points is:

[tex]Distance =\sqrt{(b-y)^2+(a-x)^2}=11 \\\\\sqrt{(b-y)^2+(a-x)^2}=11[/tex]

If Triangle ABC is then dilated by 3/4, the new coordinate is B'(3/4 (x-a) + a, 3/4 (y - b) + b). The distance between B' and the center of dilation would be:

[tex]Distance =\sqrt{(b-[\frac{3}{4}( y-b)+b])^2+(a-[\frac{3}{4} (x-a)+a])^2}[/tex]

Therefore the distance cannot be gotten until the center of dilation is given

What is the rule for the transformation below?

Answers

Answer:  T(-5, 3)

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

Explanation:

The translation notation T(-5, 3) looks like an ordered pair point, but it is not. Instead, it is a rule to tell you how to shift any point left/right and up/down. The first number is the left/right shifting as its done along the x axis. The negative value means we shift left, so we shift 5 units to the left. The positive 3 in the y coordinate place means we shift 3 units up.

We see this shifting happen when we go from

A = (-1, -1) to A ' = (-6, 2) B = (2, 3) to B ' = (-3, 6)C = (5, -3) to C ' = (0, 0)

The translation notation T(-5, 3) is the same as writing [tex](x,y) \to (x-5, y+3)[/tex] which may be a more descriptive notation to use, and it would avoid confusion with ordered pair point notation.

Insert 2 sets of parentheses to make each sentence true: 2 x 14 – 9 – 17 – 14 = 7 (2 x 14) – 9 – (17 – 14) = 7 2 x (14 – 9) + (– 17 – 14) = 7 (2 x 14) – (9 – 17) – 14 = 7 2 x (14 – 9) – (17 – 14) = 7

Answers

Answer:

  2 × (14 – 9) – (17 – 14) = 7

Step-by-step explanation:

Evaluate the choices to see which is true.

(2 x 14) – 9 – (17 – 14) = 7   ⇒  28 -9 -3 ≠ 7

2 x (14 – 9) + (– 17 – 14) = 7   ⇒  2(5) +(-31) ≠ 7

(2 x 14) – (9 – 17) – 14 = 7   ⇒   28 -(-8) -14 ≠ 7

2 x (14 – 9) – (17 – 14) = 7   ⇒   2(5)- 3 = 7 . . . . true

PLEASE HELP!! It’s for a math class and I can’t figure it out been trying every website nothing has helped!

Answers

Answer:

11.6%

I hope this helps!

when the point ( k, 3 ) lies on each of these lines, find the value of k y= 3x+1 , y= 4x-2 , y=1/2x - 1 and 2x+3y=4

Answers

Answer:

see explanation

Step-by-step explanation:

Since (k, 3) lies on each of the lines, the point satisfies the equations.

Substitute x = k, y = 3 into each and solve for k

y = 3x + 1

3 = 3k + 1 ( subtract 1 from both sides )

2 = 3k ( divide both sides by 3 )

k = [tex]\frac{2}{3}[/tex]

-------------------------------------------------------

y = 4x - 2

3 = 4k - 2 ( add 2 to both sides )

5 = 4k ( divide both sides by 4 )

k = [tex]\frac{5}{4}[/tex]

--------------------------------------------------------

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

3 = [tex]\frac{1}{2}[/tex] k ( multiply both sides by 2 to clear the fraction )

k = 6

---------------------------------------------------------

2x + 3y = 4

2k + 3(3) = 4

2k + 9 = 4 ( subtract 9 from both sides )

2k = - 5 ( divide both sides by 2 )

k = - [tex]\frac{5}{2}[/tex]

Please answer this question now

Answers

Answer:

82 degrees

Step-by-step explanation:

Measure of arc ABC = 86*2 = 172 degrees.

Measure of arc DC = 360 - (145+172) = 360-317 = 43 degrees.

Measure of arc BCD = 121+43 = 164 degrees.

Measure of angle A = 164/2 = 82 degrees

the answer is 82 degrees

If a and b are acute angles such that tan (a+b)= 1.73 and tan(a-b) =1/1.73, find a and b

Answers

[tex] \LARGE{ \underline{ \boxed{ \orange{ \rm{Solution:)}}}}}[/tex]

Given,

tan (a + b) = 1.73 [tex]\approx[/tex] √3tan (a - b) = 1 / 1.83 [tex]\approx[/tex] 1 / √3

To find:

Value of a and b in degrees....?

Solution:

☃️ Refer to the trigonometric table....

Then, proceeding

⇛ tan 60 ° = √3

⇛ tan 60° = tan (a + b)

⇛ 60° = a + b

Flipping it,

⇛ a + b = 60° --------(1)

And,

⇛ tan 30° = 1 / √3

⇛ tan 30° = tan (a - b)

⇛ 30° = a - b

Flipping it,

⇛ a - b = 30° ---------(2)

Now adding eq.(1) and eq.(2),

⇛ a + b + a - b = 60° + 30°

⇛ 2a = 90°

⇛ a = 90° / 2

⇛ a = 45°

Putting value of a in eq.(1),

⇛ 45° + b = 60°

⇛ b = 15°

☄ So, Our Required answers:

a = 45°b = 15°

━━━━━━━━━━━━━━━━━━━━

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