diff-eq for amount of salt Q at time t is dQ/dt = fQ/(V_0 + (e-f)t) = be

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I am from Turkey. My english is not very good. So ı found this site. Please help me. I have a test on Wednesday!

16. A tank initially holds V0 liters of brine (salty water) that contains a kilograms of salt. Another brine solution containing b kilograms of salt per liter is poured into the tank at the rate of e liters per minute while, simultaneously, the well-stirred solution leaves the tank at the rate of f liters per minute. The differential equation for the amount of salt Q in the tank at any time t is:

. . . . .\(\displaystyle \dfrac{dQ}{dt}\, +\, \dfrac{f}{V_0\, +\, (e\, -\, f)t}\, Q\, =\, be\)

a. A tank initially holds 100 liters of a brine solution containing 20 kilograms of salt. At t = 0, fresh water (with no salt in it) is poured into the tank at the rate of 5 liters per minute, while the well-stirred mixture leaves the tank at the same rate. Find the amount of salt in the tank at any time.

b. A tank initially holds 100 liters of a brine solution containing 1 kilogram of salt. At t = 0, another brine solution containing 1 kilogram of salt per liter is poured into the tank at the rate of 3 liters per minute, while the well-stirred mixture leaves the tank at the same rate. Find the amount of salt in the tank at any time.

c. A tank with the capacity of 50 liters contains 10 liters of fresh water (with no salt in it). At t = 0, a brine solution containing 1 kilogram of salt per liter is poured into the tank at the rate of 4 liters per minute, while the well-stirred mixture leaves the tank at the rate of 2 liters per minute. Find the amount of time required for overflow to occur. (overflow: mixture present in the tank = initial capacity, 50 liters, of the tank)
 
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I am from Turkey.My english is not very well.So ı found this site.Please help me.

16. A tank initially holds V0 liters of brine (salty water) that contains a kilograms of salt. Another brine solution containing b kilograms of salt per liter is poured into the tank at the rate of e liters per minute while, simultaneously, the well-stirred solution leaves the tank at the rate of f liters per minute. The differential equation for the amount of salt Q in the tank at any time t is:

. . . . .\(\displaystyle \dfrac{dQ}{dt}\, +\, \dfrac{f}{V_0\, +\, (e\, -\, f)t}\, Q\, =\, be\)

a. A tank initially holds 100 liters of a brine solution containing 20 kilograms of salt. At t = 0, fresh water (with no salt in it) is poured into the tank at the rate of 5 liters per minute, while the well-stirred mixture leaves the tank at the same rate. Find the amount of salt in the tank at any time.

b. A tank initially holds 100 liters of a brine solution containing 1 kilogram of salt. At t = 0, another brine solution containing 1 kilogram of salt per liter is poured into the tank at the rate of 3 liters per minute, while the well-stirred mixture leaves the tank at the same rate. Find the amount of salt in the tank at any time.

c. A tank with the capacity of 50 liters contains 10 liters of fresh water (with no salt in it). At t = 0, a brine solution containing 1 kilogram of salt per liter is poured into the tank at the rate of 4 liters per minute, while the well-stirred mixture leaves the tank at the rate of 2 liters per minute. Find the amount of time required for overflow to occur. (overflow: mixture present in the tank = initial capacity, 50 liters, of the tank)

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