Bob has five times as much money as John and together they have 60.00 what would this look like as an equation

A tank with a capacity of 1000 L is full of a mixture of water and chlorine with a concentration of 0.02 g of chlorine per liter

faltersainse [42]

At the start, the tank contains

(0.02 g/L) * (1000 L) = 20 g

of chlorine. Let c (t ) denote the amount of chlorine (in grams) in the tank at time t .

Pure water is pumped into the tank, so no chlorine is flowing into it, but is flowing out at a rate of

(c (t )/(1000 + (10 - 25)t ) g/L) * (25 L/s) = 5c (t ) /(200 - 3t ) g/s

In case it's unclear why this is the case:

The amount of liquid in the tank at the start is 1000 L. If water is pumped in at a rate of 10 L/s, then after t s there will be (1000 + 10t ) L of liquid in the tank. But we're also removing 25 L from the tank per second, so there is a net "gain" of 10 - 25 = -15 L of liquid each second. So the volume of liquid in the tank at time t is (1000 - 15t ) L. Then the concentration of chlorine per unit volume is c (t ) divided by this volume.

So the amount of chlorine in the tank changes according to

$\dfrac{\mathrm dc(t)}{\mathrm dt}=-\dfrac{5c(t)}{200-3t}$

which is a linear equation. Move the non-derivative term to the left, then multiply both sides by the integrating factor 1/(200 - 5t )^(5/3), then integrate both sides to solve for c (t ):

$\dfrac{\mathrm dc(t)}{\mathrm dt}+\dfrac{5c(t)}{200-3t}=0$

$\dfrac1{(200-3t)^{5/3}}\dfrac{\mathrm dc(t)}{\mathrm dt}+\dfrac{5c(t)}{(200-3t)^{8/3}}=0$

$\dfrac{\mathrm d}{\mathrm dt}\left[\dfrac{c(t)}{(200-3t)^{5/3}}\right]=0$

$\dfrac{c(t)}{(200-3t)^{5/3}}=C$

$c(t)=C(200-3t)^{5/3}$

There are 20 g of chlorine at the start, so c (0) = 20. Use this to solve for C :

$20=C(200)^{5/3}\implies C=\dfrac1{200\cdot5^{1/3}}$

$\implies\boxed{c(t)=\dfrac1{200}\sqrt[3]{\dfrac{(200-3t)^5}5}}$

7 0

1 year ago

There are four steps for converting the equation x2 + y2 + 12x + 2y – 1 = 0 into standard form by completing the square. complet

goblinko [34]

Let's first write each step of the procedure:
Step 1:
group the x terms together and the terms and together, and move the constant term to the other side of the equation:
x² + 12x + y² + 2y = 1
Step 2:
determine (b ÷ 2) 2 for the x and y terms.
(12 ÷ 2) 2 = 36
and
(2 ÷ 2) 2 = 1
Step 3:
add the values to both sides of the equation.
x2 + 12x + 36 + y2 + 2y + 1 = 1 + 36 + 1
Step 4:
write each trinomial to binomial squared, and simplify the right side.
(x + 6) 2 + (y + 1) 2 = 38
Answer:
the last step is:
(x + 6) 2 + (y + 1) 2 = 38

3 0

1 year ago

A bag of trail mix weighs 1.625 pounds round 1.625 to the nearest hundredths

Andrew [12]

If you round 1.625 pounds to nearest hundredths its 1.63 pounds.

7 0

2 years ago

The planetarium, which is not marked on the map, is halfway between the historic village and the science center. What are its co

lutik1710 [3]

As I have seen this question before:

Coordinates of historic village: (-4 1/2 , 5 1/2)
Coordinates of science center: (-4 1/2 , -1 3/4)

To find the midpoint, we use:
((x₂ + x₁)/2) , (y₂ + y₁)/2)
= ( (-4 1/2 + -4 1/2)/2 , (-1 3/4 + 5 1/2) / 2)
= ( -4 1/2 , 1 7/8)

6 0

1 year ago

2 A pharmacist has a 13 % alcohol solution and another 18 % alcohol solution. How much of each must he use to make 50 grams of a

nalin [4]