Answer:
Part a) 
Part b) 
Step-by-step explanation:
Part a) How many gallons of water will be in the pool after 20 minutes?
we know that
Using proportion

Part b) How many gallons of water will be in the pool after 1 hour
we know that
1 hour = 60 minutes
Using proportion

Answer:
Step-by-step explanation:
Given that acceleration of an object is

is the solution to the differential equation
Since v(0) =7
we get ln 7 = C
Hence 
since velocity is rate of change of distance s we have
![v=\frac{ds}{dt} =7e^{-2t}\\s= [tex]s(t) =\frac{-7}{2} (e^{-2t})+C)[](https://tex.z-dn.net/?f=v%3D%5Cfrac%7Bds%7D%7Bdt%7D%20%3D7e%5E%7B-2t%7D%5C%5Cs%3D%20%5Btex%5Ds%28t%29%20%3D%5Cfrac%7B-7%7D%7B2%7D%20%28e%5E%7B-2t%7D%29%2BC%29%5B)
substitute t=0 and s=0

So solution for distance is

A-2b=-10
add 2b on both sides
a=2b-10
add 10 to both sides
a+10=2b
divide both sides by 2
a/2+10/2=a/2+5=b
b=5+a/2
Answer:
Step-by-step explanation:
10^2 -4^2 = x^2
100 -16 = x^2
84= x^2
Find the square root of 84 which is approximately 9.2
The answer is 9.2