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Artemon [7]
3 years ago
9

Half of the substance to remain is called the half-life of the substance.

Mathematics
1 answer:
Sindrei [870]3 years ago
5 0

Answer:

Instructions are below.

Step-by-step explanation:

<u>To calculate the final amount if a given substance, we need to use the following formula:</u>

final amount= initial amount / (2^n)

n= elapsed time / half-life

For 20 years:

n= 20/10= 2

Final amount= 200/(2^2)

Final amount= 50 grams

For 60 years:

n= 60/10= 6

Final amount= 200/ (2^6)

Final amount= 3.125 grams

<u>To calculate the elapsed time it is more complicated:</u>

elapsed time= ln(ending amount/beginning amount) / (-decay constant)

ln= natural logarithm

decay constant= ln(2) / half-life

decay constant= 0.0693

elapsed time= ln(1.03/200) / (-0.0693)

elapsed time= 76.028

Prove:

n= 76.02/10= 7.602

Final amount= 200/(2^7.602)= 1.03 grams

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mary is eighteen years older than her son. she was three times as old as he was one year ago.How old are they now?
zimovet [89]

Answer:

<h2>The son is 10 Mary is 28</h2>

Step-by-step explanation:

I hope dis helps

4 0
3 years ago
A deck of cards contains RED cards numbered 1,2,3 and BLUE cards numbered 1,2,3,4,5,6. Let R be the event of drawing a red card,
Tatiana [17]

Answer:

e. R′

Step-by-step explanation:

Let the Sample Space be a universal set consisting of 3 red  and 6 blue cards. Then the event of  of getting 4 blue cards will be given

R complement = R` = Universal Set minus Red cards will give blue cards.

a. R OR O

It cannot be this option because we need 4 blue card

b. B AND O

It cannot be this choice as well because 4 is not odd.

c. R OR E

4 is even but we need blue

d. R AND O

Red and odd is again not required

e. R′  = It  will give our required result.

f. E′= 4 is even if it is complemented it cannot be obtained and will be left out.

5 0
3 years ago
Me need more help plz also add explanation real explanation
Reika [66]

So we want to find the surface area of this pyramid. Finding the surface area of a 3D shape is essentially finding the area of all its sides and adding them together.

What we're going to have to do here is find the area of the base of the pyramid, which is basically a square, and find the area of all four sides of the pyramid, which are triangles.

Formula for area of a square: length × width

Formula for area of a triangle: (base × height) ÷ 2

First we will find the area of the base:

l × w = A

(Write out formula)

8 × 8 =

(Input values)

A = 64 m^2 (square meters or meters squared)

(We have our answer, dont forgot to write your units.)

So we've figured out the area of the base. Now onto the triangles:

(b×h) ÷ 2 = A

(Write out formula)

(8 × 6) ÷ 2 =

(Input values)

48 ÷ 2 =

(Use PEMDAS to solve this correctly. We did whatever was in the parenthesis first, which was multiplication.)

A = 24m^2 (square meters or meters squared)

(We have our answer.)

Now we've found the area of the base of the pyramid and one of the sides of the pyramid, but we're almost done! There's four sides to the pyramid, they're all the same. So since we found the area for one, we can multiply that by 4 to find the area of all sides added together:

24 × 4

(area of a side × total sides)

= 96m^2

All that's left is adding the 96 to the area of the base to get our total surface area of the pyramid:

96 + 64 = 160

The surface area of the pyramid is 160m^2(square meters or meters squared)

(Hope this helps :) )

8 0
2 years ago
Read 2 more answers
Two lines passing through the point (2 , 3) intersect each other at an angle of 60° . If slope of one line is 2, then find the e
Lady bird [3.3K]

Hey there!

Same question is answered by me correctly.

You can go and check the answer link given:

brainly.com/question/25169246

<u>Note:</u>

The answer in the given link is answered by me.

4 0
2 years ago
Read 2 more answers
PLEASE HELP I WILL MARK BRANLIEST
liubo4ka [24]
31.62
You use pythagorean theorem so 30 is legA and 10 is legB so 20^2+10^2= square root legC which is 31.62
8 0
2 years ago
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