-12=p-7 Please help me

A tank is filled with 1000 liters of pure water. Brine containing 0.04 kg of salt per liter enters the tank at 9 liters per minu

klemol [59]

Answer:

The differential equation which describes the mixing process is $\frac{dc_{salt,out}}{dt} + \frac{2}{125}\cdot c_{salt,out} = \frac{71}{100000}$ .

Step-by-step explanation:

The mixing process within the tank is modelled after the Principle of Mass Conservation, which states that:

$\dot m_{salt,in} - \dot m_{salt,out} = \frac{dm_{tank}}{dt}$

Physically speaking, mass flow of salt is equal to the product of volume flow of water and salt concentration. Then:

$\dot V_{water, in, 1}\cdot c_{salt, in,1} + \dot V_{water, in, 2} \cdot c_{salt,in, 2} - \dot V_{water, out}\cdot c_{salt, out} = V_{tank}\cdot \frac{dc_{salt,out}}{dt}$

Given that $\dot V_{water, in, 1} = 9\,\frac{L}{min}$ , $\dot V_{water, in, 2} = 7\,\frac{L}{min}$ , $c_{salt,in,1} = 0.04\,\frac{kg}{L}$ , $c_{salt, in, 2} = 0.05\,\frac{kg}{L}$ , $\dot V_{water, out} = 16\,\frac{L}{min}$ and $V_{tank} = 1000\,L$ , the differential equation that describes the system is:

$0.71 - 16\cdot c_{salt,out} = 1000\cdot \frac{dc_{salt,out}}{dt}$

$1000\cdot \frac{dc_{salt, out}}{dt} + 16\cdot c_{salt, out} = 0.71$

$\frac{dc_{salt,out}}{dt} + \frac{2}{125}\cdot c_{salt,out} = \frac{71}{100000}$

3 0

3 years ago

Rebecca has 3 pairs of running shoes.She bought new shoelaces for each pair.How many shoelaces did she buy?

kvasek [131]

Answer: 6 shoelaces

Step-by-step explanation:

Since 1 pair of shoes has 2 shoelaces, 3 x 2 = 6

3 pairs x 2 shoelaces = 6 shoelaces

Hope this helped!

P.S. PLS give brailiest! I only have one brainliest!!

4 0

3 years ago

Read 2 more answers

Find the area of the circle r=3 ft.

Irina-Kira [14]

Answer:

28.27

Step-by-step explanation:

first you have to stablish the formula for the area of the circle, which is A=pi×radius square. Then, you have to substitute the variables and solve. the formula with the numbers plugged in would be A=3.14×3 square. Finally, solve by multiplying 3×3=9, so the formula would be 9×3.14, when multiplyed, your answer would be 28.27 if you round it.

3 0

4 years ago

Please answer questions; 9, 10, 14, 16, 17, 18, 19, 20, 25 please, or as many as you can.

Irina18 [472]

I think number 9 is 8.34 x 10 with the exponent of -6

8 0

3 years ago

Jim washes 2/3 of his car with 1/2 a bottle of soap. What fraction of the soap will he use to clean his entire car?

Sunny_sXe [5.5K]

Answer:

if he uses 1/2 for 2/3, then you can divide 2/3 and 1.2 by 2 to get the remaining soap needed to complete the wash

so to clean the last 1/3 of the car, he`ll use 1/4 of the remaining soap

the entire car needs 3/4 of a bottle of soap

3 0

3 years ago