need help answering this question

Answer:

The development of homosapiens

Explanation:

People adapted to the harsh weather by creating tools and used land bridges to spread to new regions

Answer:

the answer I know is A. different substances. hope this helps :).

Explanation:

just always study hard and God bless.

The correct responses are;

(i) Weight percent of nitrogen: 58.6%

Weight percent of oxygen: 14.65%

Weight percent of carbon dioxide: 29.59%

(ii) Volume percent of nitrogen: 64.38%

Weight percent of oxygen: 14.1%

Weight percent of carbon dioxide: 21.53%

(iii) Partial pressure of nitrogen: 19.314 psia

Partial pressure of oxygen: 4.23 psia

Partial pressure of carbon dioxide: 6.459 psia

(iv) Partial pressure of nitrogen: 19.314 psia

Partial pressure of oxygen: 4.23 psia

Partial pressure of carbon dioxide: 6.459 psia

(v) The average molecular weight is approximately 32.02 g/mole

(vi) At 20 psia, 60 °F, the density is 0.11275 lb/ft.³

At 14.7 psia, 60 °F, the density is 0.0844 lb/ft.³

At 14.7 psia, 32 °F, the density is 0.0892 lb/ft.³

(vii) The specific gravity of the mixture 0.169

Reasons:

The volume of the tank = 40 ft.³ = 1.132675 m³

Content of the tank = Carbon dioxide and air

The pressure inside the tank = 30 psia = 206843 Pa

The temperature of the tank = 70 °F ≈ 294.2611 K

Mass of carbon dioxide placed in the tank = 2 lb.

Percent of nitrogen in the tank = 80%

Percent of oxygen in the tank = 20%

(i) 2 lb ≈ 907.1847 g

Molar mass of carbon dioxide = 44.01 g/mol

Number of moles of carbon dioxide = [tex]\displaystyle \mathbf{ \frac{907.1847 \, g}{44.01 \, g/mol}} \approx 20.613 \, moles[/tex]

Assuming the gas is an ideal gas, we have;

[tex]\displaystyle n = \mathbf{\frac{206843\times 1.132674}{8.314 \times 294.2611} }\approx 95.7588[/tex]

The number of moles of nitrogen and oxygen = 95.7588 - 20.613 = 75.1458

Let x represent the mass of air in the mixture, we have;

[tex]\displaystyle \mathbf{ \frac{0.8 \cdot x}{28.014} + \frac{0.2 \cdot x}{32}}= 75.1458[/tex]

Solving gives;

x ≈ 2158.92 grams

Mass of the mixture = 2158.92 g + 907.1847 g ≈ 3066.1047 g

[tex]\displaystyle Weight \ percent \ of \ nitrogen= \frac{0.8 \times 2158.92}{3066.105} \times 100 \approx \underline{58.6 \%}[/tex]

[tex]\displaystyle Weight \ percent \ of \ oxygen = \frac{0.8 \times 2158.92}{3066.105} \times 100 \approx \underline{14.65\%}[/tex]

[tex]\displaystyle Weight \ percent \ of \ carbon \ dioxide = \frac{907.184}{3066.105} \times 100 \approx \underline{29.59\%}[/tex]

ii.

[tex]\displaystyle Number \ of \ moles \ nitrogen= \frac{0.8 \times 2158.92 \, g}{28.014 \, g/mol} \approx 61.65\, moles[/tex]

[tex]\displaystyle Number \ of \ moles \ oxygen= \frac{0.2 \times 2158.92 \, g}{32 \, g/mol} \approx 13.5\, moles[/tex]

Number of moles of carbon dioxide = 20.613 moles

Sum = 61.65 moles + 13.5 moles + 20.613 moles ≈ 95.763 moles

In an ideal gas, the volume is equal to the mole fraction

[tex]\displaystyle Volume \ percent \ of \ nitrogen= \frac{61.65}{95.763} \times 100 \approx \underline{64.38 \%}[/tex]

[tex]\displaystyle Volume \ percent \ of \ oxygen = \frac{13.5}{95.763} \times 100 \approx \underline{14.1\%}[/tex]

[tex]\displaystyle Volume \ percent \ of \ carbon \ dioxide = \frac{20.613 }{95.763} \times 100 \approx \underline{21.53\%}[/tex]

(iv) The partial pressure of a gas in a mixture, [tex]P_A = \mathbf{X_A \cdot P_{total}}[/tex]

Partial pressure of nitrogen, [tex]P_{N_2}[/tex] = 0.6438 × 30 psia ≈ 19.314 psia

Partial pressure of oxygen, [tex]P_{O_2}[/tex] = 0.141 × 30 psia ≈ 4.23 psia

Partial pressure of carbon dioxide, [tex]P_{CO_2}[/tex] = 0.2153 × 30 psia ≈ 6.459 psia

(v) The average molecular weight is given as follows;

[tex]\displaystyle Average \ molecular \ weight = \frac{3066.105\, g}{95.7588 \, moles} = 32.02 \, g/mole[/tex]

(vi) At 20 psia 70 °F, we have;

Converting to SI units, we have;

[tex]\displaystyle n = \frac{137895.1456\times 1.132674}{8.314 \times 294.2611} \approx 63.84[/tex]

The number of moles, n ≈ 63.84 moles

The mass = 63.84 moles × 32.02 g/mol  ≈ 2044.16 grams ≈ 4.51 lb

[tex]\displaystyle Density = \frac{4.51\ lb}{40 \ ft.^3} \approx \underline{0.11275\, lb/ft.^3}[/tex]

When the pressure is 14.7 psia = 101352.93 Pa, and 60 °F

[tex]\displaystyle n = \frac{101352.9\times 1.132674}{8.314 \times 288.7056} \approx 42.8247[/tex]

The mass = 47.8247 moles × 32.02 g/mol  ≈ 1531.35 grams = 3.376 lb.

[tex]\displaystyle Density = \frac{3.376 \ lb}{40 \ ft.^3} \approx \underline{ 0.0844\, lb/ft.^3}[/tex]

When the pressure is 14.7 psia = 101352.93 and 32 °F

[tex]\displaystyle n = \frac{101352.9\times 1.132674}{8.314 \times 273.15} \approx 50.5482[/tex]

The mass = 50.5482 moles × 32.02 g/mol  ≈ 1618.55 grams = 3.568 lb.

[tex]\displaystyle Density = \frac{3.568 \ lb}{40 \ ft.^3} \approx \underline{ 0.0892 \, lb/ft.^3}[/tex]

(vii) [tex]\displaystyle The \ specific \ gravity \ of \ the \ mixture \ = \frac{\frac{3066.1047\, g}{40 \, ft.^3} }{1.00} = \frac{\frac{6.7596 \, lbs}{40 \, ft.^3} }{1.00} \approx \underline{0.169}[/tex]

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Answer: identify your decision. relize you need to make a decision.

Explanation:

Answer:

True

Explanation:

Had it on my quiz

Text wrapping in spreadsheets simply means the text will be on more than one (1) line within the cell.

A spreadsheet can be defined as a file (document) which comprises cells arranged in a tabulated format (rows and columns) and it is typically used for formatting, arranging, analyzing, storing, calculating and sorting data on computer systems.

In Computer science, when a text in spreadsheets is formatted through text wrapping, the text will appear on more than one (1) line within the cell.

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Answer: If you look up its definition of eroded it'll tell you the answer should be B

Explanation:

Answer:

general duty clause

Explanation:

Answer:

Chemical Engineers determine how to transport chemicals:

TRUE

Answer:

Explanation:

Trues

Answer:

A-personal income in a year this is the answer

Answer:

  4.5 m/s = 16.2 km/h

Explanation:

The speed is the ratio of distance to time:

  speed = (180 m)/(40 s) = 4.5 m/s

Answer

I think 51.96 I hope it's help

Answer: Um, a little feedback would help, cause I'm new but if you are thanking someone, let me know and i'll thank them for you, any other questions?

Explanation:

Answer: The elastic modulus and flexural strength are found to decrease with increased porosity. Fractography studies have been undertaken to identify the role of the pores on the fracture path. The deflection and cracking behavior of concrete structure depend on the flexural tensile strength of concrete. Many factors have been shown to influence the flexural tensile strength of concrete, particularly the level of stress, size, age and confinement to concrete flexure member, etc.

Explanation:

Answer:

A CNC machine stands for Computer Numerically Controlled Machine, they are used to Machine objects in hence create items, machine parts from prototypes. Hence the CNC machines are not used for testing/Analysis

D. CNC machines.

In Engineering the following items are basically needed for and during test/Analysis

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Answer:

Explanation:

Civil engineers have become experts in creating sustainable and environmentally friendly buildings and systems. Multiplied over many communities, the energy and emissions savings can make a real difference in the environment. Other life-improving functions can also make communities better places to live.Jul 19, 2017

I can say it oxidizes gas pollutants such as hydrocarbons and carbon monoxide. It also reduces nitrogen oxides into water, hydrogen, and carbon dioxide.

Answer:

then back into the room

Explanation:

If you leave the door open, heat is merely recycled from the room into the refrigerator, then back into the room. A net room temperature increase would result from the heat of the motor that would be constantly running to move energy around in a circle.

Answer:

Explanation:

Galvanic corrosion occurs when two dissimilar metals are immersed in a conductive solution and are electrically connected. One metal (the cathode) is protected, whilst the other (the anode) is corroded. The rate of attack on the anode is accelerated, compared to the rate when the metal is uncoupled.

Explanation:

We assume the T flip-flop changes state on the rising edge of the clock input.

The first stage is connected to the clock. The second stage clock is connected to the inverse of the Q output of the first stage, so that when the first stage Q makes a 1 to 0 transition, the second stage changes state.

Answer:

I think it would be C but im not sure sorry if its wrong

Answer:

oh this happened with me to ,this will be alright just wait a bit

The first case where the power of synthesis was applied was in Chile when they had to put 100 families in houses around 40m².

It should be noted that the power of architecture is the fact that it can synthesize a complex entry to a problem.

Chilean architect Alejandro used this in building more than several houses for the poorest communities in Chile. His rigorous and innovative design approach used a social framework that laid a precedent within the profession.

During this period in Chile, a normal middle-class home was about 80m² but he built his in 40m² and it was a good home that managed the resources that were available.

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Answer:

Battery Voltage

Voltage refers to the amount of electrical potential your battery holds. The standard automotive battery in today's vehicles is a 12-volt battery. Each battery has six cells, each with 2.1 volts at full charge. A car battery is considered fully charged at 12.6 volts or higher.

Answer: Well, that's a good question. When we look around us, we tend to see what technology has done for us, and how far it is taking us. It might be disruptive, but without it there would be no high tech military weapons, and then how would we defend ourselves? There would be no technology entertainment and without that, life would be very dull. In answering your question, we can be thankful for what it is and how far it has been taking us in life.

Explanation: Please mark a brainliest if correct it helps and have meery holidays!

Answer:

17A) 52mm

17B) 132mm

17C) 67mm

18.) 34

Explanation:

For 17)

Each distance is determined by the total distances surrounding it. For example, 17A is 73mm - 21mm, which is 52mm.

For 18)

Set up the problem as an algebraic expression:

a + b + c + d = 115

Since you know 3 of the values, you can plug them in and subtract them from 115, which turns into 34.

Answer: It does make sense, because I've been involved in these careers and have a long family line of them. And other questions?

Explanation: