The "k" value should have units and should be negative.
k = -.07 / seconds
Half-Life = ln (.5) / k
Half-Life = ln (.5) / -.07
Half-Life = -.693147 / -.07
Half-Life = 9.9 seconds
(actually, wkpedia says half-life of Krypton 91 is 8.57 seconds)
elapsed time = half-life * log (bgng amt / end amt) / log (2)
elapsed time = 9.9 * log (100 / 10) / 0.30102999566
elapsed time = 9.9 * 1 / 0.30102999566
<span><span>elapsed time = 9.9 * 3.3219280949
</span>
</span><span><span><span>elapsed time = 32.8870881395
</span>
</span>
</span>
<span>elapsed time = 32.89 seconds (rounded)
Source:
http://www.1728.org/halflife.htm
</span>
Answer:
y=-0.078x^2+8.407x+-92.892
Step-by-step explanation:
but your x and y in desmo than go under the table do y1=ax^2 then under the 2 put a 1 than +bx1+c than you round your a b and c to the nearest thousandth than after that add a b and c then after you get your answer than but x^2 behind a than x behind b then nothing behind c hope this works for you
Answer:
x = -48
<em><u>hopefully i helped :)</u></em>
Answer:
The y-coordinate of point A is 
.
Step-by-step explanation:
The equation of the circle is represented by the following expression:
(1)
Where:
- Independent variable.
- Dependent variable.
, 
- Coordinates of the center of the circle.
- Radius of the circle.
If we know that 
, 
and 
, then the equation of the circle is:
(1b)
Then, we clear within (1b):
(2)
If we know that 
, then the y-coordinate of point A is:
The y-coordinate of point A is .
