a railroad car with a mass of 90,000 kg is traveling along a straight, horizontal track at a constant speed of 2 m/s. the car collides with a second railroad car, also with a of 90,000 kg that is initially at rest. The railroad cars stick together after the collision, as shown in the figure.

1) 0.5 m/s
2) 1 m/s
3) 2 m/s
​

Answer:

D. Partial pressure

Explanation:

Partial pressure is the individual pressure exerted by each gas present in a gaseous mixture. As he is measuring the pressure of each gas in the atmosphere separately, so PARTIAL PRESSURE is the exact term for his measurement.

Answer: [tex]2.69\ L[/tex]

Explanation:

Given

The initial volume [tex]V_1=2.5\ L[/tex]

Temperature [tex]T_1=298\ K[/tex]

Final temperature [tex]T_2=321\ K[/tex]

Suppose pressure is constant for this process

[tex]\therefore \dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}[/tex]

Insert the values

[tex]\Rightarrow \dfrac{2.5}{298}=\dfrac{V_2}{321}\\\\\Rightarrow V_2=\dfrac{321}{298}\times 2.5\\\\\Rightarrow V_2=2.69\ L[/tex]

Answer:

about 93 billion light years

Explanation:

The observable Universe is, of course, much larger. According to current thinking it is about 93 billion light years in diameter.

Answer:

93 miles

Explanation: We can determine the distance to the sun using the time light takes to get to Earth. Just multiply the speed of light by the amount of time it takes light to get to Earth. That's 500 seconds.

186,282 miles per second x 500 seconds = 93,141,000 miles

The sun is about 93 million miles away from Earth. It will take our fastest space shuttle moving at a constant maximum speed about 108 days to travel this same distance.

Answer:

Hydrogen (H) “burning” initiates the fusion energy source of stars and leads to the formation of helium (He).

FUSION Reaction

Explanation:

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i dont know I hope someone knows soon take care

According to molar concentration, 100 ml of 10 M solution is needed to make 1 liter of a 1 M solution.

Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.

The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.

In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of two solutions, molar concentration is found out by, M₁V₁=M₂V₂.

On substitution in above formula, V₁=1×1/10=0.1 L=100 ml.

Thus, 100 ml  of a 10 M solution is needed to make 1 liter of a 1 M solution.

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Answer:

The correct answer is - A. Ethanol reduces air pollution.

Explanation:

Ethanol is believed to be better fuel for the environment than other petroleum fuels. Ethanol emits lower carbon dioxide as it is clean smokeless fuel, and produces less or the same oxides of nitrogen and hydrocarbons.

It is produced by the process of fermentation of molasses by yeast. Mixing it with the other fuels is found to be CO2 reduces by 30% of emissions to the atmosphere.

Answer:

Answers are in the explanation

Explanation:

1) The constant pressure is necessary during a reaction. Thus, the heat released in the reaction will be = ΔH

2) The reaction described in the problem is:

1 N₂(g) + 3H₂(g) → 2NH₃(g)

The thermochemical equation involves the change in heat, as 92.6kJ are released, the heat must be wrote as another reactant, that is:

Answer:

rahul's weight

Explanation:

internet

The force is equal to the force Rahul exerts on Earth is Rahul's weight.

Force is that thing which cause a change in the motion of an object

So, Rahul exerts a force on the Earth equal to his weight.

Thus, the force is equal to the force Rahul exerts on Earth is Rahul's weight.

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Answer:C

Explanation:

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The physical evidence that indicates that there has been a chemical reaction is that the beaker changes temperature and the correct option is option C.

Neutralization is a chemical reaction in which acid and base react to form salt and water. Hydrogen (H⁺) ions and hydroxide (OH⁻ ions) react with each other to form water.

The strong acid and strong base neutralization have a pH value of 7.

The beaker gets warm which indicates that the reaction between acid and base is an exothermic reaction releasing heat energy into the surroundings.

Therefore, The physical evidence that indicates that there has been a chemical reaction is that the beaker changes temperature and the correct option is option C.

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Answer:

The amount of HC₂H3₃2(aq) in the flask after the addition of 5.0mL of NaOH(aq) compared to the amount of HC₂H₃O₂(aq) in the flask after the addition of 1.0mL is much smaller because more HC₂H₃O₂(aq) is required to react with 5.0 mL NaOH than with 1.0 mL NaOH.

Explanation:

Equation of the reaction between acetic acid, HC₂H₃O₂(aq) and sodium hydroxide, NaOH(aq) is given below:

CH₃COOH (aq) + NaOH (aq) ----> CH₃COONa (aq) + H₂O

The equation of the reaction shows that acetic acid andsodium hydroxide will react in a 1:1 ratio

Since the concentration of NaOH was not given, we can assume that the concentration is 0.01 M

Moles of NaOH in 5.0 mL of 0.01 M NaOH = 0.01 × 5/1000 = 0.00005 moles

Moles of NaOH in 1.0 mL of 0.01 M NaOH = 0.01 ×1/1000 = 0.0001 moles

Ratio of moles of NaOH in 5.0 mL to 1.0 mL = 0.00005/0.00001 = 5

There are five times more moles of NaOH in 5.0 mL than in 1.0 mL and this means that 5 times more the quantity of HC₂H₃O2(aq) required to react with 1.0 mL NaoH is needed to react with 5.0 mL NaOH.

Therefore, the amount of HC₂H₃O2(aq) in the flask after the addition of 5.0mL of NaOH(aq) compared to the amount of HC₂H₃O₂(aq) in the flask after the addition of 1.0mL is much smaller because more HC₂H₃O₂(aq) is required to react with 5.0 mL NaOH than with 1.0 mL NaOH.

Using the law of conservation of mass, the mass of carbon reacted is 54 g of carbon.

According to the law of conservation of mass, matter is neither created nor destroyed. This means that the total mass of reactants is equal to the total mass of products.

Total mass of the products = 336g + 198g = 534 g

Total mass of reactants = 480 g + x g

From the law of conservation of mass;  534 g = 480 g + x g

x g = 534 g - 480 g

x g = 54 g

Hence, 54 g of carbon reacted.

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Answer:true

Explanation:The molecular formula indicates the exact number of atoms in the molecule. The empirical formula expresses the smallest whole number ratio of the atoms in the element.

Answer:

(b) Mn2+ + 2 e- →2 Mn ℰ° = −1.18 V

Fe3+ + 3 e- → 3Fe ℰ° = −0.036 V

In order for us to have water to drink, it first needs to go through a process called the water cycle. And in that water cycle there’s a process called evaporation. Evaporation is the process by which water changes from a liquid to a gas. In order for it to rain we need clouds and clouds are made of water.  The water is heated  causing water molecules to convert into gas, that gas then goes through a process called condensation creating clouds. At some point those clouds will be full of water, and all that water will then cause the cloud to release the water molecules causing rain.

The water cycle shows the continuous movement of water within the Earth and atmosphere. It is a complex system that includes many different processes.

There are four main parts to the water cycle:

Evaporation, Convection, Precipitation and Collection.

Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam.

The water vapor or steam leaves the river, lake or ocean and goes into the air.

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A car engine produces 604 kJ of mechanical energy from fuel capable of producing 2416 kJ of energy, then efficiency of the engine is 25%.

We can calculate the efficiency by using the below equation as:

Efficiency = (Actual production / Theoretical production) × 100%

Given that,

Actual production = 604 kJ

Theoretical production = 2,416 kJ

On putting values in given equation, we get

Efficiency = (604/2,416) × 100% = 25%

Hence efficiency of the engine is 25%.

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answer : i don’t knowww :)

Right spelling:

Answer: I don’t know. :)

Answer:

Evolution in the broadest sense explains that what we see today is different from what existed in the past. Galaxies, stars, the solar system, and earth have changed through time, and so has life on earth.Something that happened in the past is thus not "off limits" for scientific study. Hypotheses can be made about such phenomena, and these hypotheses can be tested and can lead to solid conclusions. Furthermore, many key aspects of evolution occur in relatively short periods that can be observed directly—such as the evolution in bacteria of resistance to antibiotics.Laws, like facts and theories, can change with better data. But theories do not develop into laws with the accumulation of evidence. Rather, theories are the goal of science.

Explanation:

Answer:

B. The League of Nations condemned the violations but took no other action.

Explanation:

Nazi leader, Adolf Hitler violated the Treaty of Versailles by sending German military forces in Rhineland. He not only violated the Treaty of Versailles but the Locarno Pact also.

The treaty was signed in 1919 to end the war between Germany and the Allied Powers.

Even after Adolf Hitler violated the treaty, the League Nations did not take any actions.

Therefore, option B is correct.

Answer:

The answer is Ernest Rutherford.

Answer :

Good Luck

Answer:

0.95

Explanation:

trust

Answer:

equal

Explanation:

Answer:

deforestation decreases biodiversity of the forest ecosystem

Explanation:

Deforestation has to do with the process of felling trees. This process destroys forest ecosystems. Deforestation is normally carried out for the purpose of development.

An ecosystem is a self supporting unit in which living and non living things interact. The different species of plants and animals found in an ecosystem is called biodiversity.

Since organisms in an ecosystem interact among each other and with their non-living environment, destruction of the trees in the forest ecosystem leads to the loss of certain species present in the ecosystem.

For instance, climbers and animals found on tree tops are normal components of a forest ecosystem. When trees are felled and the forest ecosystem is destroyed across the world, these organisms are threatened. This leads to loss of species or loss of biodiversity.

Answer:

Here’s one possible answer:

Deforestation will likely decrease the biodiversity of the forest ecosystem. It reduces the living space and food sources for some of the organisms. Scarcity of space and food may be a threat to the population of those organisms. Over time, some species may die off, leaving fewer species in the forest.

Explanation:

Answer:

Explanation:

Ba(OH)₂ (aq) + 2HCl (aq) --> 2H₂O (l) + BaCl₂ (aq)

171 g                    2 x 36.5 g     2 x 18 g

73 g of HCl reacts with 171 g of Ba(OH)₂

125 g HCl reacts with 171 x 125 / 73 g of Ba(OH)₂

= 292.8 g of  of Ba(OH)₂

Ba(OH)₂  available is 250 g , so it is the limiting reagent .

171 g of Ba(OH)₂ forms 36 g of water

250 g of Ba(OH)₂ forms 36 x 250 / 171 g of water

= 52.63 g of water.

Scientific processes are the steps that are done to research and draw conclusions. The results of the experiments are the proposed answer to a question. Thus, option 4 is correct.

The scientific process initiates when there is a question that needs to answer and presented with observations and facts. It includes defining the question and making observations.

From the observations, the hypothesis is formed and an experiment is designed and conducted. From the research, the conclusion and the results are drawn.

Therefore, option 4. the proposed answer is called the result.

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Answer:

Hypothesis

Explanation:

Hypothesis is an educated guess as to what the answer to the question is.

(*) Sorry for my late answer but I hope this helps others that are looking for this.

I got 100%   ;)

Answer: The concentration of given solution is 11.68 M.

Explanation:

Given: Mass of solute = 10 g

Volume of solution = 25 mL

Convert mL into L as follows.

[tex]1 mL = 0.001 L\\25 mL = 25 mL \times \frac{0.001}{1 mL}\\= 0.025 L[/tex]

Number of moles is the mass of substance divided by its molar mass. The moles of sugar (molar mass = 342.3 g/mol) is as follows.

[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{10 g}{342.3 g/mol}\\= 0.0292 mol[/tex]

Molarity is the number of moles of solute present in a liter of solution.

Hence, concentration of given solution is calculated as follows.

[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\= \frac{0.0292 mol}{0.025 L}\\= 11.68 M[/tex]

Thus, we can conclude that the concentration of given solution is 11.68 M.