All categories

3 years ago

I'll appreciate you help

Mathematics

2 answers:

Anastasy [175]3 years ago

5 0

Answer:

The answer is D have a great night :)

Step-by-step explanation:

PLEASE MARK AS BRAINLIEST

sweet [91]3 years ago

4 0

The answer is d the height of the water increases 2.5 inches per second

You might be interested in

7(x — 6) = 3х +9<br><br> Helppp

Igoryamba

Answer: x=51/4
step by step explanation: ask if needed

6 0

2 years ago

Read 2 more answers

A tank contains 60 kg of salt and 1000 L of water. Pure water enters a tank at the rate 6 L/min. The solution is mixed and drain

MissTica

Answer:

(a) 60 kg; (b) 21.6 kg; (c) 0 kg/L

Step-by-step explanation:

(a) Initial amount of salt in tank

The tank initially contains 60 kg of salt.

(b) Amount of salt after 4.5 h

$\text{Let A = mass of salt after t min}\\\text{and }r_{i} = \text{rate of salt coming into tank}\\\text{and }r_{0} =\text{rate of salt going out of tank}$

(i) Set up an expression for the rate of change of salt concentration.

$\dfrac{\text{d}A}{\text{d}t} = r_{i} - r_{o}\\\\\text{The fresh water is entering with no salt, so}\\ r_{i} = 0\\r_{o} = \dfrac{\text{3 L}}{\text{1 min}} \times \dfrac {A\text{ kg}}{\text{1000 L}} =\dfrac{3A}{1000}\text{ kg/min}\\\\\dfrac{\text{d}A}{\text{d}t} = -0.003A \text{ kg/min}$

(ii) Integrate the expression

$\dfrac{\text{d}A}{\text{d}t} = -0.003A\\\\\dfrac{\text{d}A}{A} = -0.003\text{d}t\\\\\int \dfrac{\text{d}A}{A} = -\int 0.003\text{d}t\\\\\ln A = -0.003t + C$

(iii) Find the constant of integration

$\ln A = -0.003t + C\\\text{At t = 0, A = 60 kg/1000 L = 0.060 kg/L} \\\ln (0.060) = -0.003\times0 + C\\C = \ln(0.060)$

(iv) Solve for A as a function of time.

$\text{The integrated rate expression is}\\\ln A = -0.003t + \ln(0.060)\\\text{Solve for } A\\A = 0.060e^{-0.003t}$

(v) Calculate the amount of salt after 4.5 h

a. Convert hours to minutes

$\text{Time} = \text{4.5 h} \times \dfrac{\text{60 min}}{\text{1h}} = \text{270 min}$

b.Calculate the concentration

$A = 0.060e^{-0.003t} = 0.060e^{-0.003\times270} = 0.060e^{-0.81} = 0.060 \times 0.445 = \text{0.0267 kg/L}$

c. Calculate the volume

The tank has been filling at 6 L/min and draining at 3 L/min, so it is filling at a net rate of 3 L/min.

The volume added in 4.5 h is

$\text{Volume added} = \text{270 min} \times \dfrac{\text{3 L}}{\text{1 min}} = \text{810 L}$

Total volume in tank = 1000 L + 810 L = 1810 L

d. Calculate the mass of salt in the tank

$\text{Mass of salt in tank } = \text{1810 L} \times \dfrac{\text{0.0267 kg}}{\text{1 L}} = \textbf{21.6 kg}$

(c) Concentration at infinite time

$\text{As t $\longrightarrow \, -\infty,\, e^{-\infty} \longrightarrow \, 0$, so A $\longrightarrow \, 0$.}$

This makes sense, because the salt is continuously being flushed out by the fresh water coming in.

The graph below shows how the concentration of salt varies with time.

3 0

2 years ago

The table shows a function.

enyata [817]

Answer: I need this too.

Step-by-step explanation:

4 0

3 years ago

A long year-end status report for work is 130 pages long. You need to print 17 copies for a meeting next week. How much is the p

Nikitich [7]

The first thing you should do in this case is to know how much paper you need to print for the 17 copies.
We have then:
(17) * (130) = 2210
Then, you must calculate the number of reams you need:
n = (2210) / (500) = 4.42
You need 4 full reams and 42% of a fifth ream. So, the cost will be
C = (4.42) * (3.44) = 15.2048 $
The unit cost of each paper is:
Cu = (15.2048) / (2210) = 0.00688 $
answer
the paper is going to cost 0.00688 $ for those reports

7 0

2 years ago

Read 2 more answers

Mrs.Leitz spent $8.75 on new folders, f, for the 25 students in her class. Which equation shows how to find the cost of each fol

mrs_skeptik [129]

Answer:

each folder costed 0.35

Step-by-step explanation:

8.75 divided by 25 would have given you the answer

8 0

2 years ago