Answers:
13 42 m; B; 0.57 m
Step-by-step explanation:
Data:
Pool A: r = 22 ft
Pool B: D = 13.6 m
Calculations:
1. Radius of Pool A
r = 22 ft × (0.305 m/1 ft) = 6.71 m
2. Diameter of Pool A
D =2r = 2 × 6.71 = 13.42 m
The diameter of Pool A is 13.42 m.
3. Compare pool diameters
The diameter of Pool B is 13.6 m.
So, the diameter of Pool <u>B</u> is greater.
4. Compare circumferences
The formula for the circumference of a circle is
C = 2πr or C = πD
Pool A: C = 2π × 6.71 = 42.16 m
Pool B: r = π × 13.6 = 42.73 m
Pool B - Pool A = 42.73 - 42.16 = <u>0.57 m
</u>
The circumference is greater by <u>0.57 m.</u>
<span>As x approaches positive infinity, f(x) approaches negative infinity, since the graph goes down</span>
For every 50 shoppers, 25 watermelons are sold, so 50/25
Brainliest?
I'm trying to move up a rank and it would help!
Answer:
The half-life of the radioactive substance is 135.9 hours.
Step-by-step explanation:
The rate of decay is proportional to the amount of the substance present at time t
This means that the amount of the substance can be modeled by the following differential equation:
![\frac{dQ}{dt} = -rt](https://tex.z-dn.net/?f=%5Cfrac%7BdQ%7D%7Bdt%7D%20%3D%20-rt)
Which has the following solution:
![Q(t) = Q(0)e^{-rt}](https://tex.z-dn.net/?f=Q%28t%29%20%3D%20Q%280%29e%5E%7B-rt%7D)
In which Q(t) is the amount after t hours, Q(0) is the initial amount and r is the decay rate.
After 6 hours the mass had decreased by 3%.
This means that
. We use this to find r.
![Q(t) = Q(0)e^{-rt}](https://tex.z-dn.net/?f=Q%28t%29%20%3D%20Q%280%29e%5E%7B-rt%7D)
![0.97Q(0) = Q(0)e^{-6r}](https://tex.z-dn.net/?f=0.97Q%280%29%20%3D%20Q%280%29e%5E%7B-6r%7D)
![e^{-6r} = 0.97](https://tex.z-dn.net/?f=e%5E%7B-6r%7D%20%3D%200.97)
![\ln{e^{-6r}} = \ln{0.97}](https://tex.z-dn.net/?f=%5Cln%7Be%5E%7B-6r%7D%7D%20%3D%20%5Cln%7B0.97%7D)
![-6r = \ln{0.97}](https://tex.z-dn.net/?f=-6r%20%3D%20%5Cln%7B0.97%7D)
![r = -\frac{\ln{0.97}}{6}](https://tex.z-dn.net/?f=r%20%3D%20-%5Cfrac%7B%5Cln%7B0.97%7D%7D%7B6%7D)
![r = 0.0051](https://tex.z-dn.net/?f=r%20%3D%200.0051)
So
![Q(t) = Q(0)e^{-0.0051t}](https://tex.z-dn.net/?f=Q%28t%29%20%3D%20Q%280%29e%5E%7B-0.0051t%7D)
Determine the half-life of the radioactive substance.
This is t for which Q(t) = 0.5Q(0). So
![Q(t) = Q(0)e^{-0.0051t}](https://tex.z-dn.net/?f=Q%28t%29%20%3D%20Q%280%29e%5E%7B-0.0051t%7D)
![0.5Q(0) = Q(0)e^{-0.0051t}](https://tex.z-dn.net/?f=0.5Q%280%29%20%3D%20Q%280%29e%5E%7B-0.0051t%7D)
![e^{-0.0051t} = 0.5](https://tex.z-dn.net/?f=e%5E%7B-0.0051t%7D%20%3D%200.5)
![\ln{e^{-0.0051t}} = \ln{0.5}](https://tex.z-dn.net/?f=%5Cln%7Be%5E%7B-0.0051t%7D%7D%20%3D%20%5Cln%7B0.5%7D)
![-0.0051t = \ln{0.5}](https://tex.z-dn.net/?f=-0.0051t%20%3D%20%5Cln%7B0.5%7D)
![t = -\frac{\ln{0.5}}{0.0051}](https://tex.z-dn.net/?f=t%20%3D%20-%5Cfrac%7B%5Cln%7B0.5%7D%7D%7B0.0051%7D)
![t = 135.9](https://tex.z-dn.net/?f=t%20%3D%20135.9)
The half-life of the radioactive substance is 135.9 hours.