Answer:
(a) 
(b) 
Step-by-step explanation:
Given
--- Volume of tank
--- Brine solution
--- Rate in, in gallon/min
--- Rate out, in gallon/min
Required
Determine A(t)
First, calculate the rate in (R in) and (R out) in lb/min



R(out) is calculated by multiply the rate at which brine leaves the tank (lb/gal) * R2
So, we have:



The change in the amount of brin e in the tank at time t is given as:


Rewrite:

Multiply through by dt
![dA = [15 - \frac{A}{100}]* dt](https://tex.z-dn.net/?f=dA%20%3D%20%5B15%20-%20%5Cfrac%7BA%7D%7B100%7D%5D%2A%20dt)
Make dt stand alone


Express as exponents

Multiply through by 100



Apply initial conditions

Substitute 0 for t in: 





Substitute 15 for c in 


Factorize:

How long to empty the tank
Set A to 0

Divide through by 1500

Collect Like Terms

Take ln of both sides



Answer:
C) 10
Step-by-step explanation:
hope it helps youuuuuu
Answer:
Use this
Step-by-step explanation:
The surface area of the table tennis ball will be around 1256.64 mm².
<h3>What is the sphere?</h3>
A sphere is a 3D geometrical object which has a radius and becomes a point that revolves around a fixed point called the center.
A sphere has surface area and volume based upon the radius of the sphere.
For example, if you have a sphere of radius r then its surface area will be 4πr² and volume will be (4/3)πr³.
The table tennis ball is the form of a sphere.
Given that,
The diameter of a table tennis ball is 20
Radius(r) = 20/2 = 10 mm
Surface area of an sphere = 4πr²
So,
Area = 4π(10)² = 1256.64 mm².
Hence "The surface area of the table tennis ball will be around 1256.64 mm²".
For more about a sphere,
brainly.com/question/9994313
#SPJ6
B. Because of the slope and where it the lines intersect the y axis