Answer:
243,000 people
Step-by-step explanation:
First, what we need to do is to calculate the area of the region using the 5-mile radius
Mathematically, we can calculate this as the area of a circle
Area = pi * r^2
Our r here is 5 miles
Area = pi * 5^2 = pi * 25 = 78.54 square miles
Now to get the population, we know that per square mile we have 3,100.
Hence per 78.54 square mile, we have 78.54 * 3100 = 243,273 people
To the nearest thousand, 243,000
The position function of a particle is given by:
The velocity function is the derivative of the position:
The particle will be at rest when the velocity is 0, thus we solve the equation:
The coefficients of this equation are: a = 2, b = -9, c = -18
Solve by using the formula:
![t=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-b%5Cpm%5Csqrt%5B%5D%7Bb%5E2-4ac%7D%7D%7B2a%7D)
Substituting:
![\begin{gathered} t=\frac{9\pm\sqrt[]{81-4(2)(-18)}}{2(2)} \\ t=\frac{9\pm\sqrt[]{81+144}}{4} \\ t=\frac{9\pm\sqrt[]{225}}{4} \\ t=\frac{9\pm15}{4} \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20t%3D%5Cfrac%7B9%5Cpm%5Csqrt%5B%5D%7B81-4%282%29%28-18%29%7D%7D%7B2%282%29%7D%20%5C%5C%20t%3D%5Cfrac%7B9%5Cpm%5Csqrt%5B%5D%7B81%2B144%7D%7D%7B4%7D%20%5C%5C%20t%3D%5Cfrac%7B9%5Cpm%5Csqrt%5B%5D%7B225%7D%7D%7B4%7D%20%5C%5C%20t%3D%5Cfrac%7B9%5Cpm15%7D%7B4%7D%20%5Cend%7Bgathered%7D)
We have two possible answers:
We only accept the positive answer because the time cannot be negative.
Now calculate the position for t = 6:
Answer:
21 kilometers
Step-by-step explanation:
Let the height be 
. Then, the length of the base is 
. The formula for the area is of the triangle is given by base*height/2. Therefore, the area of the triangle is equal to 
, which is in turn equal to 441. Since must be positive, then 
, meaning that the height is 
kilometers.
Answer:
=20000000 (let me know if it's incorrect)
Step-by-step explanation:
