Find the half-life, in days, of Co-60. Round your
answer to the nearest tenth.
Cobalt-60 is used in the treament of
cancer. A sample contains 8 grams of Co-
60 where k = 0.1308.
Enter the correct answer.
N = Noe -kt
DONE
No = initial mass (at time t = 0)
DOO
(อ
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

Answers

Answer 1

Answer:5.3

Step-by-step explanation:

Why

Divide both sides by 8

4=8e ^-0.1308t

0.5=e^-0.1308t

Take log of both sides

In0.5=Ine^-0.1308t

Apply In e^x=x

In0.5=-0.1308

Divide both sides by -0.1308 to solve for t

t=5.3


Related Questions

PLEASE HELP GIVING BRAINLIEST

Answers

Answer:

A.10,4

B.5,10

C.5,5

D4,4

Step-by-step explanation:

KERE ON LERNER?

Find the additive inverse and the multiplicative inverse, if it exists, of the given number. 5 in modulo 8 arithmetic

Answers

The additive inverse of 5 modulo 8 is the number a such that

5 + a ≡ 0 (mod 8)

Then

a ≡ -5 ≡ -5 + 8 ≡ 3 (mod 8)

The multiplicative inverse is m such that

5m ≡ 1 (mod 8)

Use the Euclidean algorithm:

8 = 1•5 + 3

5 = 1•3 + 2

3 = 1•2 + 1

Then

1 = 3 - 1•2

1 = 3 - 1•(5 - 1•3) = 2•3 - 1•5

1 = 2•(8 - 1•5) - 1•5 = 2•8 - 3•5

and so

1 ≡ 2•8 - 3•5 ≡ (-3)•5 (mod 8)

which means the inverse of 5 is

-3 ≡ 8 - 3 ≡ 5 (mod 8)

9.2 less than 3 times a number is the same as 21 1/4

Answers

Answer:

10.15

Step-by-step explanation:

3x-9.2 = 21.25

3x = 30.45

x = 10.15

Answer:

10.15

Step-by-step explanation:

I took the K12 test

find measurement 1 and 4

Answers

Answer:

the info they gave us is to suppose that angle 6 is = 126°

step 1:

We know that angle 8 = angle 6 = 126°

Why? — when a circle (360°) is split by 2 lines that intersect, there will be 2 equal pairs of angles formed

step 2:

angle 2 = angle 8 = 126°

Why? — they’re alternate angles

step 3:

angle 4 = angle 2

Why? — when a circle (360°) is split by 2 lines that intersect, there will be 2 equal pairs of angles formed

step 4:

angle 1 = 180-126 (angle 4) = 54°

Why? — total angles in a straight line = 180°

Key Term:

Alternate angles:

Alternate angles are angles that occur on opposite sides of the transversal line and have the same size. Alternate angles are equal: We can often spot interior alternate angles by drawing a Z shape: There are two different types of alternate angles, alternate interior angles and alternate exterior angles.


Which distance formula or formulas show(s) a joint variation?

Answers

Answer:

II and III only

Step-by-step explanation:

One variable quantity is said to vary jointly as a number of other variable quantities, when it varies directly as their product.

If $2,940.00 is invested for 4 months at 3.8% simple interest:
What is the amount of interest earned?

Answers

Answer:

I = $372.40

Step-by-step explanation:

Given the principal amount of $2,940, which is invested for 4 months at 3.8% interest rate:

Use the following simple interest formula to solve for the interest earned:

I = P × r × t

where:

I = interest earned

P = principal amount invested = $2,940

r = interest rate = 3.8% or 0.380

t = time = 4/12 months = ⅓ or 0.3333

Substitute to given values into the simple interest formula:

I = P × r × t

I = $2,940 × 0.380 × 0.3333

I = $372.40

Therefore, the simple interest earned in 4 months is $372.40.

$200 is shared between Bill and Ann. Ann’s share is $50 more than Bill’s share. Calculate the size of each of their shares.

Answers

First subtract the difference between the two:

200 - 50 = 150

Now divide that by 2:

150/2 = 75

Bills share is $75

Now add the $50 to 75 to get Ann's share:

75 + 50 = $125

Ann's share is $125

Bill's share is $75

Can someone check my work?

Answers

Answer:

See below:

Step-by-step explanation:

Hello! My name is Galaxy and I will be helping you today!

We can check your answer in 1 step.

We need to find how much they earn if they worked 37 hours at a rate of 26 dollars per hour.

We can mutliply to figure this out:

[tex]37*26=962[/tex]

Therefore, yes, your answer is correct!

Cheers!

Answer:

$26=1hr

x   =37hr

$26 x 37=$ 962

Step-by-step explanation:

what is the equation of the line that is perpendicular to y=-1/4x-2 and goes through the point (-2,-3)

Answers

Step-by-step explanation:

y=-1/4x-2

1/4x+y+2=0.........1

line perpendicular to eqn 1 is

x-1/4y+k=0

as the line passes through the (-2,-3)

-2-1/4×-3+k=0

-1+4k=0

K=1/4

the eqn is 4x-y+1=0

simplify
21m^2−122m+112/9m^2−196

Answers

Answer:

3m-8/7m+14

Step-by-step explanation:

Tom is reviewing his cell phone bill. When he gets to the text message part he notices that he send 1 text message in October,7 text messages in November, 49 messages in December,and 343 text messages in January. what kind of sequence is this?
a. arithmetic b. geometric c. both d. neither​

Answers

Answer:

it is c. both i guess anyways thanks

i hope you passed and sorry for taking your points

Step-by-step explanation:

Solve the equation for x:
x2 = 196

Answers

Answer: x= 1/196

Step-by-step explanation:

Two numbers have a sum of 18. Their product is 72. Find the numbers

Answers

Answer:

Step-by-step explanation:

x + y = 18

y = 18 - x

xy = 72

x(18 - x) = 72

-x² + 18x = 72

0 = 72 - 18x + x²

x = (18 ± √(18² - 4(1)(72))) / (2(1))

x = (18 ± 6)/2

x = 12

x = 6

Two of the angles in a triangle measure 58 degrees and 25 degrees. What must be the measure of the third angle?

Answers

97 degrees

add up the two and subtract by 180

how many ten thousand are in 1,000,000?​

Answers

Answer:

100

Step-by-step explanation:

10,000 * 100 = 1,000,000

So there are 100 ten thousands in 1,000,000

What is 11 divided by 1/4

Answers

44 i think if not really sorry

Can someone tel me if the answers are correct ? Please

Answers

Answer:

huuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuh

For the two numbers listed, find two factors of the first number such that their product is the first number and their sum is the second number -12,-1

Answers


-4 x 3 = -12
-4 + 3 = -1

The low temperature on a certain day is 56°F. The low temperature is 14°F lower than the high temperature, h. Which equation can be used to find the high temperature for that day? o 56 = h – 14 Oh + 56 = 14 O 56 = 14h 0 56 = h + 14 WHOEVER ANSWER GETS BRAINLESS NEED HELP​

Answers

Answer: 1.09

Step-by-step explanation:

2x+3-3=-6



x=3 ? Solve

Answers

[tex]2(x)+3-3=-6\\2(3)+3-3=-6\\6+3-3=-6\\6=-6\\[/tex]

[tex]x\neq 3[/tex]

As we can see, x cannot be equal to 3 as 6 cannot equal -6.

I hope I've helped! :)

What is the perimeter of a rectangle with a length of 11.25 inches and a
width of 8 inches?

Answers

Answer:

38.5 in

Step-by-step explanation:

11.25 in + 11.25 in + 8 in + 8 in

= 38.5 in

What is the value of y in y = 2x - 5, when x = 3.9?

Answers

Answer:

Y = -3 and with x as 3.9 y equals 2.8

Step-by-step explanation:

A bag of sugar weighs 6²/⁵. What is the weight of 6¹/⁴ of such bag?
How many two thirds are there in 4¹/³?

Answers

Answer:

6 and a half 2 thirds are in 4 1/3

Step-by-step explanation:

2/3x=13/3

2x=13

x=6.5

Suppose that the radius of a sphere is divided by 9. What happens with the surface area?

Answers

Answer:

Rad/9

Step-by-step explanation:

Which is an x-intercept of the graph of the

Answers

Answer:

(5π/8, 0)

Step-by-step explanation:

x intercept occurs when y = 0

0 = tan(x - 5π/8)

as tan0 = 0

x - 5π/8 = 0

x = 5π/8

sara buys two bags of chips and three boxes of pretzels for $ 85. He then buys another bag of chips and two more boxes of pretzels for $ 50. Find the cost of each bag of chips and each box of pretzels.

Answers

Answer:

Chips= $20    Pretzel=$15

Step-by-step explanation:

Sara bought 2 Chips + 3 Pretzels = $85

(Extra) 1 Chips + 2 Pretzels = $50

Pretzels are twice as much as chips so above ^^ Can be expressed

as Pretzel (15) + Pretzel (15) + Chips(20) = $50

Now lets go back to the first line Putting in the new prices

Chips(20) + Chips(20) + Pretzel(15) + Pretzel(15) = Pretzel(15) = $85

Which choice is equivalent to the expression below?

5 SQR7-4x SQR7-xSQR7

A. 0
B.-2xSQR7
C.-X^2
D. 5 SQR 7 -5xSQR7

Answers

I think is the B, tell me if it's correct OK i'm trying to help

Answer:

5√7-5x√7

Step-by-step explanation:

HELP i need what is 4 divided by 120000 telll me plz in tried the calculator but my parents blocked the calculator on me so plz help me

Answers

1/30000 there you go!

5) Placido pulls a rope attached to a wagon through a pulley at a rate of q m/s. With dimension as in Figure 5:

(a) Find a formula for the speed of the wagon in terms of q and the variable x in the figure.

(b) Find the speed of the wagon when x=0.6 if q=0.5 m/s.

Answers

The formula for the speed of the wagon can be found by using Pythagoras theorem, and chain rule of differentiation.

[tex](a) \ \mathrm{The \ speed \ of \ the \ wagon} , \ \dfrac{dx}{dt} = q -\dfrac{x}{\sqrt{x^2+ 5.76}}[/tex]

(b) When x = 0.6 and q = 0.5 m/s, the speed of the wagon is approximately 0.243 m/s.

Reasons:

(a) The distance from the cart to the pulley, r is given by Pythagoras's

theorem as follows;

r = √((3 - 0.6)² + x²) = √(2.4² + x²)

The speed of the wagon = [tex]\mathbf{\dfrac{dx}{dt}}[/tex]

The speed of the rope, q = [tex]\mathbf{\dfrac{dr}{dt}}[/tex]

By chain rule, we have;

[tex]\dfrac{dr}{dt} = \mathbf{\dfrac{dr}{dx} + \dfrac{dx}{dt}}[/tex]

[tex]\dfrac{dr}{dx} = \dfrac{x}{\sqrt{x^2+ 5.76}}[/tex]

Therefore;

[tex]\dfrac{dr}{dt} = q =\dfrac{x}{\sqrt{x^2+ 5.76}}+ \dfrac{dx}{dt}[/tex]

[tex]\mathrm{The \ speed \ of \ the \ wagon} , \ \dfrac{dx}{dt} = \underline{ q -\dfrac{x}{\sqrt{x^2+ 5.76}}}[/tex]

(b) The speed of the wagon when x = 0.6 if q = 0.5 m/s is given as follows;

[tex]\dfrac{dx}{dt} = 0.5 -\dfrac{0.6}{\sqrt{0.6^2+ 5.76}} =\sqrt{\dfrac{1}{17} } \approx 0.243[/tex]

The speed of the wagon when x = 0.6 and q = 0.5 m/s, [tex]\dfrac{dx}{dt}[/tex] ≈ 0.243 m/s

Learn more here:

https://brainly.com/question/17081984

Find the exact value of the expression below
Sec 30degrees Cos 30degrees - tan 60degrees cot 60degrees ​

Answers

Answer:

0

Step-by-step explanation:

1×2÷√(3)×√(3)÷2 - √(3)×1÷√(3)

1-1

0

for more refer to the image

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