How does the law of conservation of mass apply to smoke?

The Law of Conservation of Mass is a physical law that states that the total mass of reactants is equal to the total mass of products. This means that one form of matter is just converted to a different form, and as long as nothing escapes the system before or after the reaction, the total mass of the entire system remains constant.

The Law of Conservation of Mass can easily be observed when the reactants are all solids and the products are all solid -- as there will be no molecule that will escape the system, even if the reaction, if possible, is performed in an open environment. Perhaps a similar scenario is mixing sugar in a glass of water. Assuming no evaporation and condensation, one can take the mass of the glass with water, and the mass of sugar. Then, sugar is mixed into the water. The mass of the glass with the sugar water in it should equal the first mass.

It becomes more tricky, at first glance, when dealing with gases. For instance, burning. Burning something results in the formation of ashes and smoke. This reaction, however, involves gases that can escape the system and thus not be directly measured or easily measured in terms of mass. Burning requires oxygen as a reactant, and burning in an open environment does not allow for calculation of the amount of oxygen involved. Then, after burning, smoke is generated -- smoke is a mixture of various gases like carbon monoxide and methane, and in some cases a mixture of hydrocarbons.

Hence, at least at first glance, it might appear to someone that the law does not apply or is violated, but it is in fact not violated if only the oxygen reacted and the smoked produced is accounted for. If this is done in a closed system where all reactants are controlled and the amount is known, and the gas produced is not allowed to escape, the mass throughout the reaction will remain constant.

In short: The law of conservation of mass applies to smoke. Smoke is generated by burning. Burning requires oxygen. It is the reaction of oxygen with the burned material and the production of ash and smoke. The law of conservation of mass states that the mass of the material and the mass of oxygen consumed is equal to the mass of all products, the mass of ashes and smoke.

In The Far and the Near, how does the engineer feel about the little house and the two women in the story?

In the story, the engineer views the two women and their little house as a "beautiful and enduring" inspiration to him; throughout his railroad career, he has always idealized the women and house as the epitome of innocence and perfection. The house has always had "an air of tidiness, thrift, and modest comfort" to it, and the women remind him of everything that is wholesome and good about the female gender.

The engineer had known much toil and trouble in his days. In his service, he had seen at least four tragedies unfold before his eyes. In looking back, he remembers the tormented and stunned faces of those facing death, as the train barreled towards them. He also remembers a body flung past his window after it was presumably hit by the train. Yet, throughout all these tragedies, the women and the house had always comforted him and given him the courage to continue in his work.

He remembers that he imbibed great happiness from seeing them every time his train passed by the women's house. So, he resolves to meet with them when his long years of service with the railroad is over. Alas, his meeting with the women is marred by reality. The women are not at all welcoming or pleasant. Instead, they are sullen, aloof, and hostile. When the engineer leaves them, he finds himself bereft of hope and joy. His path in life has suddenly become clouded and his future uncertain.

Why did Juliet consume the poison?

In William Shakespeare's Romeo and Juliet, the main characters by these very same names intend to run away together because their parents forbid their love. They seek the help of Friar Laurence, who gives Juliet a sleeping potion which will make her appear to be dead. The plan is that once she is "dead" from the potion, she will be laid out in the family tomb, where Romeo can visit her and take her away. However, Romeo doesn't know the whole plan! Friar Laurence sends a letter explaining what should happen, but Romeo never receives it. Instead, he hears that Juliet is dead, and goes to her tomb to die alongside her. He drinks some poison he has brought, and moments after his death, Juliet awakens-- according to plan. She is so overcome by Romeo's dead body that she takes his dagger and kills herself with it.

Sometimes Juliet's sleeping potion is referred to as a poison, but as we see by the fact that she wakes, it was not a fatal one.

In respect to globalization, how has your global perspective been expanded over the past several years, and what has caused that expansion?

Our global perspective has expanded over the years for a variety of reasons. One way that our global perspective has expanded is with the growth of businesses beyond our borders. We are realizing that we must be competitive internationally. This has become painfully clear, as companies have moved jobs overseas to save on labor costs. Workers in some other countries, such as Mexico, China, and India, are paid less than American workers. This has led to jobs being shipped overseas, and/ or American workers having to take pay and benefit cuts. It also means our calls to customer service or technical support centers may not be handled in the United States.

Another example of our expanding global perspective can be seen in the increase in the number of terrorist attacks throughout the world. Many of these recent attacks have occurred in places that normally haven’t experienced these attacks. France, Belgium, and Germany are some countries where these attacks have occurred. These recent attacks have required our government and the American people to be very vigilant because these attacks could occur here in the future. The attacks on September 11, 2001, in New York, Washington, D.C., and Shanksville, Pennsylvania made us realize we are vulnerable to possible terrorist attacks. The recent attacks have reminded us of this vulnerability. Fighting terrorism will take a global effort.

The impact of civil wars in other countries has also expanded our global perspective. We realize these conflicts create issues with refugees who want to come here to escape the strife in their homelands. We need to develop policies about how to handle these refugees. We also need to try to prevent the conditions that often help lead to the outbreak of civil wars. The issue with the Syrian refugees is one we are currently trying to face.

Finally, as we try to take actions to protect our environment, we realize this must be a global effort. Some countries have less restrictive rules regarding pollution. We are trying to work together with other countries to deal with issues such as global warming and pollution control. As the global climate changes, it will have an impact throughout the world. Global cooperation is needed to deal with these issues.

Explain what happens to the blood in the ventricles when the muscle in the ventricle walls contracts.

When blood enters the heart it first enters the atria, which are above the ventricles. The right atrium receives blood that is returning from the body and is low in oxygen. The left atrium receives blood that is returning from the lungs where it has just gained oxygen. The atria contract first and push the blood down into the ventricles.

The cardiac muscle in the ventricles is thicker and stronger, and when the ventricles contract, the blood is forced out of the heart. The blood from the right ventricle goes to the lungs to pick up oxygen, and the blood from the left ventricle leaves the heart through the aortic valve and the aorta. The blood will travel through the arteries that get progressively smaller until it is in the capillaries where diffusion will occur to bring oxygen and nutrients to the cells.

This is a continually cycling process that depends on precise timing of muscle contractions to keep the blood circulating smoothly.

What would be the consequences of trash becoming a biotic factor?

The consequences of trash becoming a biotic factor would be devastating for the environment. By definition biotic factor is a living organism which interacts with other organisms and the environment to shape it in some way. Entire ecosystems would crumble and life would drastically change for all living organisms.

Currently trash is an abiotic factor in the environment, meaning it plays a role but has no active relationship with other living organism through deliberate choice. Trash piles in the United States are largely contained in landfills in semi-urban environments. In 2013 the US had 1,903 landfills with nearly half of those in the western states. Some landfills are being used to generate a positive impact on the environment by producing energy through natural gas via decomposition of organic material.

One key factor of landfills is that they are contained areas for garbage collection. As a biotic factor the trash would hold some sort of decision making process and have the capability to interact with the world. Suppose a landfill in New Jersey decided it wanted to move to Texas? Or even just take up more room? As a biotic factor the trash might grow like a plant and have no direct communication, but may fight for its own survival which may clash with humanity. 

Such a factor is far fetched, but can help encourage people to think about recycling. Even local trash could create a problem if it becomes a biotic factor. Trash outside of a landfill may congregate in an area like the middle of wetlands or neighborhood to ensure its survival. One of the key points to remember is all living things have an instinct to thrive. Higher conscience animals such as human can forgo those instinct to a certain degree, but even on a biological level the human body was made to survive. Thus, trash would assume some such need to survive. How that need arises would be the problem.

Theoretically, trash would eventually find a balance in an ecosystem and the environment would gain stasis. However, not all organisms reach stasis through the same means. Viruses (there is still debate whether they are living or non-living), for example, will destroy a host before moving on to another target. The number of hosts exposed to infection will create stasis in the long run, but some hosts will die in the process. What happens if trash turns out to be more like a virus than a human?

What is the signal that Katniss and Rue use to alert each other that they are still safe?

The portion of the book that your question is asking about can be found in chapter sixteen.  Rue tells Katniss about the signal that she sends to the workers in her district.  The signal is a four note melody that Rue sings, and the mockingjays repeat the melody all around the orchard.   Rue teaches Katniss the four note mockingjay melody, and they agree to use the mockingjay four note sequence to signal that everything is okay.  

The book does not explain what the four notes are, but the reader is under the impression that Katniss uses those exact notes.  Interestingly, the movie has Katniss practice and use an entirely different four note signal from what Rue taught her.  Also Katniss doesn't sing the notes like Rue does.  Instead, Katniss whistles.  

Rue's four note melody in the movie is Db - F - Eb - Gb.

The four note melody that Katniss whistles in the movie is G - Bb - A - D.