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Aleks [24]
2 years ago
9

a radioactive substance has a half-life of 2 seconds. A scientist begins with a sample of 20 grams. How much of the substance re

mains after 8 seconds?
Mathematics
1 answer:
s344n2d4d5 [400]2 years ago
5 0

Answer:

1.25 g

Step-by-step explanation:

you start with 20g at 0 seconds.

divide by half after 2 seconds and you have 10g.

at 4 seconds you have 5g.

at 6 seconds you have 2.5g.

at 8 seconds you have 1.25g.

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PLEASE HELP ASAP!!! WILL GIVE BRAINLIEST ANSWER!!!!!!
ladessa [460]

7 * 68 =476

7 * 60 = 420

7 * 8 = 56

add together

476

Jo is correct

4 0
3 years ago
suppose that eight terms of a wire are wrapped around a pipe with a length of 60 in and a circumference of 4 inches so that the
EastWind [94]
The length of the wire is the length of the hypotenuse of a triangle with one leg 60 inches and the other leg 8*4 in = 32 inches.

√(60² +32²) = √4624 = 68

The wire is 68 inches long.

_____
Consider what happens if you wrap a paper triangle of those dimensions around the pipe. The hypotenuse edge traces the path of the wire.
4 0
3 years ago
What can be multiplied to get 40 but also added to get 29​
Tresset [83]

Answer:

is that even possible.

Step-by-step explanation:

4 0
3 years ago
Five years ago I was 5 times older than my son. In 8 years’ time I will be 3 times older than my son. How old am I today?
o-na [289]

Let x = Parent's age now  y = son's age now

Then, x-5 = parent's age five years ago

        y-5 = son's age five years ago

     So, x-5 = 5(y-5)

          Simplify to get x - 5y = -20

Parent's age 8 years from now = x+8

Son's age 8 years from now = y+8

    So, x+8 = 3(y+8)

           Simplifying, we have x - 3y = 16

We have the system of equations:  x - 5y = -20

                                                  x - 3y = 16

Subtract the equations to obtain -2y = -36

                                                  y = 18

                                                  x = 70

Parent is 70 years old and the son is 18 years old.  

6 0
3 years ago
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DanielleElmas [232]
4 hours she spent .............:
3 0
3 years ago
Read 2 more answers
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