The half-life of a certain radioactive element is 35 hours. If there are 904 grams of this element, how much will be left after 70 hours? PLEASE HELP I MIGHT FAIL MATH.

Answers

Answer 1
Answer: 226 grams

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

Explanation:

The half-life is 35 hours. This means every 35 hours, the amount of the substance is cut in half. If we started with 100 grams, then 35 hours later, we will have 50 grams. Then another 35 hours later we will then have 25 grams, and so on.

In this case, we start with 904 grams and follow this sequence:

904, 452, 226, 113, ...

Each term is cut in half. Going from term to term it takes 35 hours each. The third term 226 is the result of waiting two half-lives, which is 2*35 = 70 hours that have elapsed total.

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

If you want to use a formula, then it would be

[tex]y = A*\left(\frac{1}{2}\right)^{x/H}[/tex]

where,

H = half-life duration (in this case, it is 35)

A = starting amount (which is 904 in this case)

x = amount of time that has elapsed (we will plug in x = 70)

y = final amount after x units of time has elapsed

note that x and H must have the same time unit. Both are in terms of hours in this case.

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

So we will plug A = 904, x = 70, H = 35 into the formula to get...

[tex]y = A*\left(\frac{1}{2}\right)^{x/H}\\\\y = 904*\left(\frac{1}{2}\right)^{70/35}\\\\y = 904*(0.5)^{2}\\\\y = 904*(0.25)\\\\y = 226\\\\[/tex]

We see that x = 70 leads to y = 226. This means after 70 hours, there is 226 grams of the material left.


Related Questions

add or subtract (7x^2-x-2)-(-6x^3+3)

Answers

Answer:

[tex] \tt{}6x ^{3} + {7x}^{2} - x - 5[/tex]

Step-by-step explanation:

[tex] \tt{}(7 {x}^{2} - x - 2) - ( - 6 {x}^{3} + 3)[/tex]

[tex] \tt{}7 {x}^{2} - x - 2 + 6x^{3} - 3[/tex]

[tex] \tt{} {7x}^{2} - x - 5 + 6x ^{3} [/tex]

[tex] \tt{}6x ^{3} + {7x}^{2} - x - 5[/tex]

Answer:

[tex]6 {x}^{3} + 7 {x}^{2} - x - 5[/tex]

Step-by-step explanation:

[tex](7 {x}^{2} - x - 2) - ( - 6 {x}^{3} + 3)[/tex]

➡️ [tex]7 {x}^{2} - 2 - ( - {6}^{3} + 3)[/tex]

➡️ [tex]7 {x}^{2} - x - 2 + 6 {x}^{3} - 3[/tex]

-2 - 3-(2 + 3)-5

➡️ [tex]7 {x}^{2} - x - 5 + 6 {x}^{3} [/tex]

➡️ [tex]6 {x}^{3} + 7 {x}^{2} - x - 5[/tex] ✅

Please help with this

Answers

Answer:

A

Step-by-step explanation:

what is the property for (s + 2) +4​

Answers

Answer:

s+6

Step-by-step explanation:

You just add 2 and 4.

Answer:

Associative

Step-by-step explanation:

(s+2)+4 = s + (2 + 4)

s + 6 = s + 6

There are 90 chickens on the farm. If 60% of the animals on the farm are chickens, how many animals are on the farm? Pls help asap!

Answers

Answer:

150

Step-by-step explanation:

You need to add 60 to the 90 and then check it by doing 60% of 150.

Hope this helps.

Answer: 150 is the answer

Step-by-step explanation:

what is the difference between - 21 and -8 on a number line?

Answers

the difference is 13

Answer:

They are 13 units apart. -8 is closer to zero while -21 is farther ways from zero.

Need help please owo with all of them

Answers

First one d second c and third one a

Answer:

d, c and a

Step-by-step explanation:

O///O

Fond the equation of the line shown

Answers

Answer:

y+-1/2x-1

Step-by-step explanation:

The line is negative

It rises one digit and runs 2

and it crosses though -1 on the y axis

Can someone help with this

Answers

Answer:

the answered is -3 like in the picture

Step-by-step explanation:

What type of skew does this graph have?

Answers

Answer:

Negative skew; skewed right.

Step-by-step explanation:

It is a negative skew, because the peak of the graph is located towards the left (5- 9, respectively). The skewed is on the right, for the tail stretches out to the right of the graph (10-14 all the way to 25 - 29, respectively).

~

Please can’t Gail this

Answers

Answer:

4

Step-by-step explanation: because you up four and move 1 so the answer is 4/1 but is simplified by 4

4 I think haven’t done in a while but rise over run is how I learned so -4/-1 simplified is 4

Solve: 5/9 + (-4/5)

Answers

Answer:

-11/45

Step-by-step explanation:

5/9 + (-4/5)

25/45 + (-36/45)

(Multiplied each side by opposite denom.)

25/45 -36/45

Simplify

25-36=-11

-11/45

Cannot simpfily

Answer:

Step-by-step explanation:

5/9 + (-4/5)

-11/45 or − 0.244444444 and on and on forever

Finding Distances from the Mean
The mean of the data is 44.7. Complete the chart to find the distances from the mean.
Of
Temp (°F)
2938
45
31
50
58
62
Distance
from the
Mean
15.7
6.7
13.7
y
13.3

Answers

Answer:

x = 0.3, y = 5.3, z = 17.3

Step-by-step explanation:

Since given question is incomplete, so here is the complete table for the distance from the mean.

Temp (°F)                              29      38       45    31      50     58     62    

Distance from the mean    15.7    6.7       x    13.7      y     13.3       z

It's given that the mean of the data is 44.7

Since distance from the mean of a data is the absolute value of the difference of data and mean,

Therefore, distance from the mean of the data will be,

x = |44.7 - 45| = 0.3 (absolute value of the difference)

y = |44.7 - 50| = 5.3

z = |44.7 - 62| = 17.3

Answer:

x =   0.3

y =   5.3

z =   17.3

Step-by-step explanation:

Help please will give brainly! Clara’s friend Brian decides to find his median as well. Find the median and type it in the answer box. What does the median show us?

Answers

Answer:

The median is 88. The median shows that Brian gets on average 88% on his tests.

Step-by-step explanation:

If you put the numbers in order and get the average of the two middle number, it is 88.

A stack of 12 bricks is 27 inches high. How high is each brick?

Answers

Answer: 2.25 inches

Step-by-step explanation:

27/12= 2.25

What is the mode of 4, 9, 9, 9, 4, 6, 6, 6, 9?

Answers

Answer:

9

Step-by-step explanation:

That's the most common number there

Answer:

9

Step-by-step explanation:

The mode of a set of data values is the value that appears most often.

in this set, 9 appears 4 times -> 9 is mode

233 is equal to r more than 48?

Answers

I think it’s equal to .hope that helps

Answer:

R = 152

Step-by-step explanation:

what i did was if it is talking about more than 48 something plus 48 is 200 so

200 - 48 = 152

r = 152

so 200 is 152 more than 48

Hope this helpsBrainliest plzAsk any more math questions if you want

Simplify the radical expression (3 + √6) (3 - √6)

Answers

Answer:

3

Step-by-step explanation:

(3 + √6) (3 - √6) = 9-3√6+3√6-6 = 9-6 = 3

(pls mark brainliest fam)

Answer:

3

Step-by-step explanation:

use FOIL method. ;)

You are wakeboarding on a river. You travel 2 miles downstream to a marina for supplies, and then you travel 3 miles upstream to a dock. The boat travels x miles per hour during the entire trip, and the river current is 3 miles per hour.

How long will the trip take when then speed of the boat is 18 miles per hour? Round to the nearest tenth minute.

Answers

Answer:

17.3

Step-by-step explanation:

(2+18)=(20mph*2miles)=6 minute

(18-2)=16mph*3miles=11.25

17.25

Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.


Zack delivers mail for the post office. Every day he walks a 7-mile route. How many miles does Zack walk in one month if he works 22 days that month?


Solve the problem. Multiply 22 and 7 and you 154 and that's your answer


154 miles

Answers

Answer: 154

Step-by-step explanation:

Hi, to answer this question we simply have to multiply the distance that he walks every day (7 miles) by the number of days that he works in a month (22).

Mathematically speaking:

7m x 22d = 154 miles  

Zack walks 154 miles in one month.

Feel free to ask for more if needed or if you did not understand something.

30 students apply for a scholarship,
10 have college degrees
18 have school certificates
8 have both qualifications.
(a) Draw a Venn diagram to show thi
information.
(b) How many students have no
qualification?​

Answers

Answer:

A - school certificates

B - college degrees

So 30 - (10 + 8 + 2) = 10 have no qualification

In July 2008, a wildfire near Yosemite
National Park burned about 53 square
miles of forest. If one square mile equals
640 acres, about how many acres of
forest were burned?

Answers

I’m not positive but do 53 times 640 and you should get the answer

Zayne has a bag filled with coins. The bag contains 7 quarters, 8 dimes, 3 nickels, and 9 pennies. He randomly chooses a coins from the bag. What is the probability that Zayne chooses a quarter or a nickel?

Answers

10/27

hope this helps :)

Answer:

Q=7/27 N=1/9 which is 10/27

Step-by-step explanation:

you add all the coins together

then if it is quarter then it is 7/27

if it is a nickel then it is 3/27 = 1/9

Lily wants to buy a new smartphone. She has $500 to spend. List three ways she can get a good deal.

Answers

Answer:

get a coupon find a cheap on or steal it or get a discount

Answer:

She could use coupon deals, she could research what stores have it cheapest, see what deals online has

1. On a quiet day without many witnesses, a 4.5 ft victim is shot by a sniper that
was in a tower 780 ft away. If the angle of elevation is 48° from the victim, at
what vertical distance did the sniper shoot from?

Answers

Answer:

The sniper shoot from 870.775 feet vertical distance.

Step-by-step explanation:

Refer the attached figure

Height of victim = AB = 4.5 ft.

Distance between tower and victim BC = 780 feet

The angle of elevation =[tex]\angle DAE = 48^{\circ}[/tex]

Let DE be x

AB = CE = 4.5 feet

BC =AE = 780 feet

Height of tower = DE+CE=x+4.5

In ΔDAE

[tex]\frac{Perpendicular}{Base}=Tan\theta\\\frac{DE}{AE}=Tan 48^{\circ}\\\frac{x}{780}=1.11061\\x=1.11061 \times 780\\x=866.275[/tex]

Height of tower = DE+CE=x+4.5=866.275+4.5=870.775 feet

Hence  the sniper shoot from 870.775 feet vertical distance.

Ade has two similar scale models of the same pyramid. The first model has a
height of 5 inches and a surface area of 80.9 square inches. The linear dimensions
of the second model are each increased by a common factor so that the height of
the second model is 15 inches. To the nearest tenth of a square inch, what is the
surface area of the second model?

Please help!

Answers

Answer: 242.7 square inches

Step-by-step explanation:

Hi, to answer this question we have to apply proportions:

The first model has a height of 5 inches and a surface area of 80.9 square inches:

The proportion is : height/ surface area= 5 in / 80.9 in2

For a height of 15 inches

15 in/ x in2

So:

5/80.9 = 15/x

x= 15/ (5/80.9 )

x= 242.7 square inches

Feel free to ask for more if needed or if you did not understand something.  

Consider the following polynomial.
-2xys + 3x? - 10x°y6 + 8x + 4
Which of the following statements are true? Select all that apply.
-The polynomial has 5 terms.
-The leading coefficient is -2.
.
-The degree of the polynomial is 7.
-The constant term is 4.
-The polynomial is in decreasing degree order.

Answers

Answer:

Step-by-step explanation:

If you write correctly:

[tex]P = -2xys+3x? - 10xy^{6} +8x+4\\[/tex]

I do not know the "?" in the formule de P

-The polynomial has 5 terms.  Yes

-The leading coefficient is -2. No

.

-The degree of the polynomial is 7.  Yes

-The constant term is 4.  Yes

-The polynomial is in decreasing degree order. No

What does the word ‘Denotation’ mean?

Answers

Answer: Depends on what your talking about so I'll give all 3 definitions.

Step-by-step explanation:

1.)The literal or primary meaning of a word, in contrast to the feelings or ideas that the word suggests.

-Used in a sentence- Beyond their immediate denotation, the words have a connotative power.

2.) When used in philosophy it means, the object or concept to which a term refers, or the set of objects of which a predicate is true.

3.) And, the last definition is, the action or process of indicating or referring to something by means of a word, symbol, etc.

find the output, y, when the input, x, is -5.​

Answers

Answer:

y = -2

Step-by-step explanation:

When x = -5

Go to the blue line

y = -2

Answer:

There are 2 questions with the same question but with a different graph.

This graphs answer is -2.

But the other graph that people are confused about is 7.

Step-by-step explanation:

Hope this helps! :)

6 customers entered a store over the course of 18 minutes. At what rate were the customers entering the store in customers per minute?

Answers

Answer:

3 minutes

Step-by-step explanation:

18 divided by 6 = 3 minutes

Hope this helps :)

There are 30 marbles in a bag. You randomly choose 20 marbles from the bag. The results are shown in the table. Predict the total number of red marbles.

Color
Blue 6
Red 12
Yellow 2
There are about how many red marbles?

Answers

Answer:

12 because if you add 6 and 12

Step-by-step explanation:

hope it helps uou !!

Answer:

It's 12

Step-by-step explanation:

hope it helps you !!

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