2/4%8/10 can someone help me in this one

A 500-gallon tank initially contains 220 gallons of pure distilled water. Brine containing 5 pounds of salt per gallon flows int

Wittaler [7]

Answer: The amount of salt in the tank after 8 minutes is 36.52 pounds.

Step-by-step explanation:

Salt in the tank is modelled by the Principle of Mass Conservation, which states:

(Salt mass rate per unit time to the tank) - (Salt mass per unit time from the tank) = (Salt accumulation rate of the tank)

Flow is measured as the product of salt concentration and flow. A well stirred mixture means that salt concentrations within tank and in the output mass flow are the same. Inflow salt concentration remains constant. Hence:

$c_{0} \cdot f_{in} - c(t) \cdot f_{out} = \frac{d(V_{tank}(t) \cdot c(t))}{dt}$

By expanding the previous equation:

$c_{0} \cdot f_{in} - c(t) \cdot f_{out} = V_{tank}(t) \cdot \frac{dc(t)}{dt} + \frac{dV_{tank}(t)}{dt} \cdot c(t)$

The tank capacity and capacity rate of change given in gallons and gallons per minute are, respectivelly:

$V_{tank} = 220\\\frac{dV_{tank}(t)}{dt} = 0$

Since there is no accumulation within the tank, expression is simplified to this:

$c_{0} \cdot f_{in} - c(t) \cdot f_{out} = V_{tank}(t) \cdot \frac{dc(t)}{dt}$

By rearranging the expression, it is noticed the presence of a First-Order Non-Homogeneous Linear Ordinary Differential Equation:

$V_{tank} \cdot \frac{dc(t)}{dt} + f_{out} \cdot c(t) = c_0 \cdot f_{in}$ , where $c(0) = 0 \frac{pounds}{gallon}$ .

$\frac{dc(t)}{dt} + \frac{f_{out}}{V_{tank}} \cdot c(t) = \frac{c_0}{V_{tank}} \cdot f_{in}$

The solution of this equation is:

$c(t) = \frac{c_{0}}{f_{out}} \cdot ({1-e^{-\frac{f_{out}}{V_{tank}}\cdot t }})$

The salt concentration after 8 minutes is:

$c(8) = 0.166 \frac{pounds}{gallon}$

The instantaneous amount of salt in the tank is:

$m_{salt} = (0.166 \frac{pounds}{gallon}) \cdot (220 gallons)\\m_{salt} = 36.52 pounds$

3 0

3 years ago

The sum of two numbers is 97. One number is 1 more than twice the other number. Find the two numbers.

guajiro [1.7K]

Answer:

The 2 numbers are 32 and 65.

Step-by-step explanation:

x + y = 97 where x and y are the 2 numbers.

x = 2y + 1

Substituting for x in the first equation:

2y + 1 + y = 97

3y = 96

y = 32.

So x = 2y + 1 = 64 + 1 = 65.

4 0

4 years ago

4 divide by8/9 - 1/2

Sever21 [200]

I think 4 divided by 8/9 - 1/2 = 4

6 0

3 years ago

Determine which postulate can be used

Kruka [31]

Answer:

SAS postulate

Step-by-step explanation:

The triangles have two congruent sides and one congruent angle. The congruent angle is the included angle. This meets SAS criteria.

Hope this helps :-)

3 0

3 years ago

Rational numbers are natural numbers. always sometimes never

kupik [55]

Answer:

sometimes

Step-by-step explanation:

rational numbers can sometimes be natural since all natural numbers also rational but not all rational numbers natural

6 0

4 years ago