Element X decays radioactively with a half life of 11 minutes. If there are 870 grams
of Element X, how long, to the nearest tenth of a minute, would it take the element to
decay to 154 grams?
y = a(.5) t/h​

Answers

Answer 1

Answer:

27.5 minutes

Step-by-step explanation:

Using,

R/R' = 2ᵃ/ᵇ------------------ Equation 1

From the equation,

R = mass of Element X before radioactive decay, R' = mass of element X after radioactive decay, a = Time taken, b = half life.

Given: R = 870 grams, R' = 154 grams, b = 11 minutes.

Substitute these values into equation 1

870/154 = 2ᵃ/¹¹

(870/154)¹¹ = 2ᵃ

Solve for a

2ᵃ = (5.649)¹¹

2ᵃ = 187061.26

Taking the logarithm of both side,

Log2ᵃ = Log(187061.26)

⇒ a = log(187061.26)/log2

a = 8.272/0.301

a = 27.5 minutes


Related Questions

SOCCER PRACTICE BEGAN AT 2:30 P.M 3:30 P.M THROUGH WHAT FRACTION OF A CIRCLE DID THE MINUTE HAND TURN HOW MANY DEGREES DID THE MINUTE HAND TURN

Answers

Answer:

1 /1 ; 360°

Step-by-step explanation:

Start time = 2:30 pm

Stop time = 3:30 pm

Minute hand makes a complete revolution per hour ;

This means that the minutes hand revolves round the whole circle in one hour, hence fraction of the circle covered by the minute hand between 2:30 pm - 3:30 pm is 1/1 = 1

The angle turned by the minutes hand :

1 complete revolution = 360°

A circle covers 360°

1 /1 fraction of a circle = 1/1 * 360° = 360°

Hence, angle turned by the minute hand = 360°

T or F:
When finding the percentage of each section, you have to divide the part by the whole or total amount.

Answers

Answer:

true because you can do that in a amound of the total

Which solution for z makes the equation true?? 10+10+z=40=10 (pls explain why. Thanks)

Answers

Answer:

z=30

Step-by-step explanation:

40-10=30

10+10+?=30

30-10-10=10

I'm sorry cuz I don't know how to explain it

Answer:

z = 10

Step-by-step explanation:

10 + 10 + z = 40 - 10

10 + 10 + z = 30

10 + 10 + 10 = 30

since 40 - 10 = 30, then Z has to equal 10 because 10 + 10 + z needs to be 30

A recent study sought to determine if exercising after studying for an exam may help retain information. The 150 student volunteers that participated in the study were randomly assigned to three groups. All students were given a picture memory task that they studied for 15 minutes. After studying, one of the groups was instructed to exercise for 30 minutes immediately after studying. A second group was instructed to wait 1 hour after studying and then exercise for 30 minutes. The third group was instructed to not exercise after studying. The next day all 150 student volunteers were given a test to determine how well they could remember what they studied. Here are the results:

Answers

Answer:

The correct answer is (A).

Step-by-step explanation:

Because the data came from 3 groups in a randomized experiment, the appropriate test is a chi-square test for homogeneity.

help me understand please​

Answers

Answer:

V=pi x (r)^2 x h

V-volume r-radius h-height

V= pi x (3)^2 x 9

V= pi x 9 x 9

V= pi x 81

V= 254.47 (rounded)

Factor the expression (s):

7x+63

12x+15

36z+60

Answers

The answer for the first one is 7(x+9)
The answer for the second one is 3(4x+5)
The answer for the third one is 12(3z+5)

12% of what number is 1044?

Answers

8,700*

12/100=1044/y         Equation

1044 x 100= 104,400       Cross multiply

104,400÷12=8700            Divide quotient by pecentage out of 100 (12)

What is the surface area of the prism below?
A
216 ft2

B
312 ft2

C
432 ft2

D
10,800 ft2

Answers

the answer is C 432 ft 2

Someone solve this please

Answers

Answer:

the pyramid is 80 ft² and the rectangular prism is 240 ft²

Step-by-step explanation:

Find the product of -3/5× .-1.5 .
[tex] - \frac{3}{5} \times - 1 .5[/tex]

Answers

Answer:

bit.[tex]^{}[/tex]ly/3a8Nt8n

Step-by-step explanation:

how do I graph this linear equation?
4x+6y=-12​

Answers

Answer: Simplifying

Step-by-step explanation:

Simplifying

4x + 6y = 12

Solving

4x + 6y = 12

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-6y' to each side of the equation.

4x + 6y + -6y = 12 + -6y

Combine like terms: 6y + -6y = 0

4x + 0 = 12 + -6y

4x = 12 + -6y

Divide each side by '4'.

x = 3 + -1.5y

Simplifying

x = 3 + -1.5y

Then you get your answer I think or hopeful get your answer. I hoped this helped!

20 points helppppppppppppppppppppppppppppp

PLZZ anyone solve this ASAP​

Answers

Answer:

[tex] cos^{-1}(cos\frac{ 7π}{6})=cos^{-1}(cos\frac{7*180}{6})[/tex]

[tex] cos^{-1}(cos{210})[/tex]

[tex] cos^{-}(cos(180+30))[/tex]

[since in third quadrant cos 30=-[tex] \frac{\sqrt{3}}{2}][/tex]

[tex] cos^{-}(- \frac{\sqrt{3}}{2})[/tex]

:150°or [tex] \frac{5π}{6}[/tex]

150°or [tex] \frac{5π}{6}[/tex]is a required answer.

What divided by 76 equals 127

Easy one please answer ASAP

Answers

Answer is : 9692

cxcvbnm

What is the equation of the graph below?


y = sec(x – 4)
y = sec(x) – 4
y = sec(x + 4) + 4
y = sec(x + 4) – 4

Answers

Answer:

It's A don't listen to the other guy

Step-by-step explanation:

Answer:

A

Step-by-step explanation:

edg 22

The sheet of metal has dimensions 56 cm by 33 cm. It sis melted down
and recast into discs of the same thickness and radius 7 cm. How many
disces will be cast ?

Answers

Answer:

12 discs

Step-by-step explanation:

Sheet metal has dimensions of 56 cm by 33 cm. This indicates that it is a rectangle.

A_rectangle = length × width

A_rect = 56 × 33

A_rect = 1848 cm²

It is now melt down and recast into disc's of 7 cm radius and similar thickness.

Thus;

Area of one disc = πr² = π × 7² = 49π

Thus,number of disc's cast = 1848/49π

number of disc's cast = 12

Find the Minimum & Maximum values of the given function over the interval (-1,
4].
y = e^x+1

Answers

Answer:

answer in photo

Find the Area of the composite figure below:

Answers

Answer:

24

Step-by-step explanation:

added all the sides hope this helps

Rectangle ABCD is congruent to rectangle A″B″C″D″ . Which sequence of transformations could have been used to transform rectangle ABCD to produce ​ rectangle A″B″C″D″ ​ ? ​ Rectangle ABCD ​ was reflected across the y-axis and then across the x-axis. ​ Rectangle ABCD ​ was translated 8 units left and then 7 units down. ​ Rectangle ABCD ​ was translated 2 units left and then 3 units down. ​ Rectangle ABCD ​ was rotated 180° around the origin and then translated 7 units down. A coordinate graph with rectangle A B C D and rectangle A double prime B double primes C double prime and D double prime. Rectangle A B C D has points at A begin ordered pair 2 comma 5 end ordered pair, B begin ordered pair 2 comma 2 end ordered pair, C begin ordered pair 6 comma 2 end ordered pair, D begin ordered pair 6 comma 4 end ordered pair. Rectangle A double prime B double prime C double prime D double prime has points at A double prime begin ordered pair negative 6 comma negative 3 end ordered pair, B double prime begin ordered pair negative 6 comma negative 5 end ordered pair, C double prime begin ordered pair negative 2 comma negative 5 end ordered pair, D double prime begin ordered pair negative 2 comma negative 3 end ordered pair

Answers

Answer:- A. Rectangle ABCD was translated 8 units left and then 7 units down.

Explanation:-
We can see vertex A(2,4) of rectangle ABCD moves to A"(-6,-3), in a way that A translated 8 units left (-8)and 7 units down(-7) to A".
i.e.(2-8,4-7)=(-6,-3)
Similarly the other vertices of rectangle ABCD moves to form rectangle A"B"C"D"
B (2,2) → B" (-6,-5)
C (6,2) → C" (-2,-5)
D(6,4) → D" (-2,-3)

Helppp I really need this question answered

Answers

Answer:

32.5 units²

Step-by-step explanation:

We can find the area by dividing the figure into two shapes. If we solve for the area of a square and a triangle, we can add them together.

First, we can solve for the area of the 5x5 square. To find the area, we can multiply the two dimensions.

5 · 5 = 25 units²

Next, we can find the area of the triangle. It has an equal height to the square, so the height of the triangle is 5 units. The width isn't specified. Instead, we are shown that the width of both the square and the triangle equals 8 units. If we subtract the width of the square from the total, we can find the width of the triangle, too.

8 - 5 = 3

So, the height and the width of the triangle are 5x3. To find the area we can multiply these together, and then divide the product by two.

5 · 3 = 15

[tex]\frac{15}{2}[/tex] = 7.5

The area of the triangle is 7.5 units².

Finally, we can add the area of the triangle and the square together.

25 + 7.5 = 32.5

The area of the figure, then, is 32.5 units².

The answer is the last option.

I hope this helps ^^

please help thank u alot going to put pictures!

Answers

1/4 divided by 5= 0.05 or 1/20
1/5 divided by 2= 0.1 or 1/10
5 divided by 1/2=2.5 or 2 1/2
4 divided by 1/3 = 12

which side is opposite the middle size angle give the letter name ​

Answers

Answer:

opposite of 55 degrees would be KL

opposite of 97 degrees would be ML

opposite of 28 degrees would be MK

Step-by-step explanation:

mark me brainliest if right!!!

A metal bar weighs 24 ounces. 15% of the bar is gold. How many ounces of gold are in the bar? *​

Answers

Answer:

7.6 ounces of silver

Step-by-step explanation:

Hope this helps :)

There ae 3.6 ounces of Gold in the metal bar.

What is mean by Percentage?

A number or ratio that can be expressed as a fraction of 100 or a relative value indicating hundredth part of any quantity is called percentage.

To Calculate the percent of a number , divide the number by whole number and multiply by 100.

Given that;

A metal bar weighs 24 ounces.

And, 15% of the bar is gold.

Now, We can formulate as;

Amount of gold in the bar is,

⇒ 15% of 24

⇒ 15/100 × 24

⇒ 3.6 ounces

Hence, There ae 3.6 ounces of Gold in the bar.

Learn more about the percent visit:

https://brainly.com/question/24877689

#SPJ2

PLSSS HELPPPP I WILLL GIVE YOU BRAINLIEST!!!!!! PLSSS HELPPPP I WILLL GIVE YOU BRAINLIEST!!!!!! PLSSS HELPPPP I WILLL GIVE YOU BRAINLIEST!!!!!! PLSSS HELPPPP I WILLL GIVE YOU BRAINLIEST!!!!!!PLSSS HELPPPP I WILLL GIVE YOU BRAINLIEST!!!!!! PLSSS HELPPPP I WILLL GIVE YOU BRAINLIEST!!!!!! PLSSS HELPPPP I WILLL GIVE YOU BRAINLIEST!!!!!!

Answers

Answer:

Function 1 has the greatest rate of change.

Step-by-step explanation:

The rate of change is also known as the slope.

Slope is rise over run: change in y over change in x.

Function 1's slope: 3 / 2

Function 2's slope: (0 - (-4)) / (5 - (-5)) = 4/10 = 2/5

3/2 > 2/5

Function 1 has the greatest rate of change.

find the 6th term of 6, 8, 32/3

Answers

Answer:

The 6th term of the sequence is 6144/243

Step-by-step explanation:

From what we have, we can see that the sequence might be geometric

to confirm this, we have to check if the common ratio is the same all through

To know this, we have to divide the succeeding term by the preceding term and check if the results for two sets are equal

thus, we have it that;

32/3 * 1/8 = 8/6

= 4/3 = 4/3

We can confirm that the sequence is thus geometric

Now, to find the nth term of a geometric sequence, we have it that;

Tn = ar^(n-1)

where a is the first term, given as 6

r is the common ratio given as 4/3

n is the term number given as 6

Thus, we have this as:

T6 = 6 * (4/3)^(6-1)

T6 = 6 * (4/3)^5

T6 = 6144/243

Can some plz help me

Answers

This is a guess but I think 24 hope I helped :))

HELPPPPPPPPPPPPPPP!!!!!!!

Answers

i think it’s -2 and 10 but sorry if i am wrong btw the 10 is on the left and -2 on the right

Answer:

I feel like the answers are 10 and -2

Step-by-step explanation:

Hope this helps! Have a great day and good luck! :)

How could you calculate the value of log11(9100) using a calculator? What does it equal (round to the nearest tenths place)?

Answers

I don’t know gjcdjdveudvdudhsvudbfvfif

what is the area of the figure below

Answers

Answer:

Step-by-step explanation:

this is sorta a thought process to figure this out.   so think it thur with me.  b/c they are saying that the line is the same length with the lines thur it... see them?  so then that means that two sides of the right triangle are of a certain length so that means we know the base and length of the sides of a box, if we were to add the other right triangle to it.. see that?

so we can say that  6*7.5 = box   and we'll have two total boxes, see that?  the top portion of the parallelogram and the bottom are each a box .. but cut down the middle and put as two opposite parts of a triangle.

so

2*(6*7.5) = 90 [tex]in^{2}[/tex]

if given a radius of 6mm, what is the diameter?

if given a diameter of 22ft, what is the radius?

Answers

Answer:

If the radius is 6mm, the diameter is 12mm.

If the diameter is 22 ft, the radius is 11 ft.

Step-by-step explanation:

1st one) When you try to find the diameter of any circle, and you already have the radius, you need to multiply it by two (double it)

6 x 2 = 12mm

2nd one) Then to do the opposite, you need to divide the diameter by 2.

22/2 = 11 ft

Hope this helped :)

5x + 1 = 6x - 8 x= como puedo resolverla

Answers

Answer:

X = 9

Step-by-step explanation:

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