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:
80 mph
Step-by-step explanation:
<u>First leg of trip</u>
- Speed = 64 mph
- Time = 3 hours
<u>Second leg of trip</u>
- Speed = 92 mph
- Time = 4 hours
To find the average speed:
We have that
case 1) 2x3 + 4x -----------> <span>C. cubic binomial
</span>The degree of the polynomial is 3----> <span>the greater exponent is elevated to 3
</span>the number of terms is 2
<span>
case 2) </span>3x 5 + 3x 4 + x 3--------> <span>A. Quintic trinomial
</span>The degree of the polynomial is 5----> the greater exponent is elevated to 5
the number of terms is 3
<span>
case 3) </span>x 2 + 3----------> <span>B. quadratic binomial
</span>The degree of the polynomial is 2----> the greater exponent is elevated to 2
the number of terms is 2
<span>
case 4) </span>2x 2 + x − 5 A------------> D. quadratic trinomial
The degree of the polynomial is 2----> the greater exponent is elevated to 2
the number of terms is 3
Let's turn this sentence into an equation:
8n = -n + 36
Then solve:
9n = 36 => n=4
