They are all being multiplied by 4
A) -18
B) 129
C) 40
D) -9
E) -8
Ending Amount = Beginning Amount * e^k*t
5 grams = 100 grams * e^-.00043 * years
We have to solve the equation for "years"
(You can find the formula here: http://www.1728.org/halflif2.htm
or you can just read the next line
time = natural log (bgng amt / endg amt) / k
time = natural log (100 / 5) / .00043
time = natural log (20) / .00043
time = 2.9957322736 / .00043
time =
<span>
<span>
<span>
6,967</span></span></span><span> years
</span>
We should double-check this.
First, we need the half-life
k = ln(.5) / half-life
half-life = <span>-.693147 / -.00043
half-life = 1,612 years
Now let's see how many half-lives that is:
</span><span>6,967 / 1,612 years = 4.2 half-lives
So basically, after 4 half-lives the mass should go from
100
50 1 half life
25</span><span><span> 2 half lives</span>
12.5 </span><span>3 half lives
</span> 6.25 <span>4 half lives</span>
6.25 is very close to 5 grams so we can assume we have calculated correctly.
Answer:
Well the cases ... lets seee the cases show.... well I CAN NOT SEE THE CASES
Step-by-step explanation:
