What is a good thesis for the poem ''The convergence of the twain''?

I usually find that a good rule for creating thesis statements about poems is to fill in this sentence: In ["Poem's Title,"] [Author's Name] uses [literary device], [literary device], and [literary device] in order to convey the idea that [central purpose].  A well-developed thesis should include not only the poem's main message (or central purpose) but also the ways in which the poet produces and conveys that purpose (the literary devices employed to achieve it).  

A good thesis might look something like this: In "The Convergence of the Twain," Thomas Hardy employs metaphor, form, and a particularly descriptive title to convey the idea that the sinking of the Titanic was the inevitable result of humanity's pride.

The facts that it was "human vanity" that conceived of the Titanic and our "Pride" that planned the ship are referenced in the first stanza (lines 2-3).  Further, the comparison of the iceberg to a "mate" for or a partner of the Titanic helps to convey the idea that they are meant to come together (19).  The phrases "intimate welding" (27) and "twin halves" (30), as well as the word "consummation" (33) also emphasize the idea that the ship and iceberg amounted to two parts of one whole.  The idea of mates, of intimacy, and of consummation (a physical union, but also an ultimate end) all lead to the idea of the two seemingly "Alien," or unrelated, things actually being designed for one another (25).  

Further, the title uses the word "Convergence" which is not typically how we would think of the coming together of the Titanic and the iceberg.  We might call it a crash or a sinking or something that employs a more violent or tragic connotation, but "Convergence" actually just means moving to join together  -- again, the idea of the two things being destined to combine is clear.  Moreover, the word "Twain" means a pair or couple, and so this matches the meanings of "mates" and "twin halves" too.

Finally, each stanza of the poem employs end rhyme, where the last word of each of the three lines rhymes with the others.  This rhyme scheme makes it seem as though the three lines "belong" together.  Plus, the first and second lines of each stanza are significantly shorter than the third line, and this actually makes each stanza look like the shape of a ship or an iceberg above the water.  More importantly, though, is that the first line's length combined with the second line's length would equal the third line's length.  The first and second lines, when combined in length, come together to approximately equal the third line's length.  This also enhances our reading of the poem by repeating, again and again, a coming together of two things to equal something larger: just as the Titanic and iceberg converged to create "one august event" (30).

Why is wind speed measured in knots and not mph?

This is because you are talking about the movement of a fluid, not a solid.  Wind is composed of air, which, like water, is classified as a fluid.  Since wind and water are both fluid, they are measured by the same unit.

The old sailing ships used a knotted rope which was being pulled off a spool to determine how fast they were moving through the water.  The sailors didn't have any familiar landmarks to sight, so they had to improvise with the materials they had aboard the ship to gauge their speed.  Similarly, wind speed doesn't cover ground in the same fashion something like a land vehicle does, such as a truck or car. 

An airplane traveling through the wind, with a strong tailwind pushing it along, finds the going easy, actually faster than if the situation were reversed and it was flying into the wind; a headwind would slow the airplane down.  This is similar to the way ocean waves speed or slow the motion of ships. 

The patterns of winds also pulse, which means the speed is not constant, which would also make it sensible to use knots for speed measurement, not miles per hour, because terrain traveled is constant, not pulsing like wind.

What were the effects of the Dust Bowl?

The Dust Bowl had a dramatic effect on agriculture in the United States. The event was an ecological disaster caused by generations of misuse of the land. A sustained drought ruined farmland across four states as heavy winds picked up the topsoil and carried it for miles in dust clouds. A mass exodus to the west occurred as farms became worthless. Over sixty percent of the population of the effected area moved from the region. This had its own set of problems as states to the west were not prepared for the influx of new migrants.

Despite the loss of farms and the crippling impact that it had on the economy, the Dust Bowl did mark a positive change in American history. This was the desire of the federal government to manage farmland and prevent future ecological disaster by subsidizing farmers. This meant that farmers would receive government money to not plow over essential grasslands. Farmers also received bonuses for responsible use of the land. The federal government also purchased land to set aside as protected land to prevent future soil problems.

What is a chemical component of urine?

Numerous biochemical processes create by-products which must be removed from the body. The kidneys filter these by-products from the blood through the production of urine. Normal urine is 91-96% water, plus a variety of compounds and ions, including urea, chloride, sodium, potassium, calcium and creatine. Various proteins and hormones may also be present. 

A chemical is a substance which can be represented by a chemical formula. Chemical components of urine are thus urea (CH4N2O), creatine (C4H9N3O2), creatinine (C4H7N3O) and ammonia (NH4). Glucose (C6H12O6) may also be present in urine. Although, high levels of urine glucose may be indicative of diabetes or pre-diabetes. 

In cases of disease, other non-chemical substances that might be present in urine include red or white blood cells and bacteria. 

What is going to be put in the cornerstone of the new bank?

Towards the end of Art I (right after Emily asks her mother whether she is pretty and they have a conversation about that subject) the Stage Manager tells the audience that "the Cartwright interests" have just started building a new bank in Grover's Corners. The date of the first act is May 7, 1901. They have asked a friend of the Stage Manager for suggestions about what they should put in the cornerstone of the new building. Evidently the intention is to put these artifacts in a metal time capsule and encase it in a block of concrete. They have already decided to put in a copy of the New York Times and a copy of the local newspaper, The Sentinel. They are putting in a Bible, the Constitution of the United States, and a book of William Shakespeare's plays. They are thinking the cornerstone might not be dug up by archaeologists for a thousand years and that people would be interested in what life was like a thousand years earlier. 

The Stage Manager tells the audience that he is going to have a copy of the play they are presently performing, i.e., Our Town, placed in the cornerstone so that people a thousand years from now--around the year 2901--will know some simple facts about the people of his town. This seems to be the playwright Thornton Wilder's intention in writing this very simple but very moving play. It is a sort of tribute to small-town America. The slow pace of the play mimics the slow pace of small-town life in a place like Grover's Corners in New Hampshire (Population 2,642). Wilder does a very good job of capturing the spirit of a typical small New England town with its humdrum daily routines and occasional tragedies. The Stage Manager expresses the author's intention when he says:

This is the way we were in our growing up and in our marrying and in our living and in our dying.

The three acts of the play are largely concerned with those three things--marrying, living, and dying. 

Angus and Ross approach Banquo and Macbeth with great news. How and why do Banquo and Macbeth respond after Ross gives them the good news? What do...

After the witches tell Macbeth and Banquo the prophecy (that Macbeth will become Thane of Cawdor and later king, and that Banquo's children will becomes kings), they run into Ross and Angus. The men give news that the King has decided to make Macbeth Thane of Cawdor. This is good news, of course, but it also shows that the prophecy might actually be true.

The two men react differently. Macbeth believes the prophecy and asks Banquo if he wants his children to be kings. Banquo distrusts the witches and comments that the devil often tells half truths. The two men agree to speak on the prophecy later in private. Macbeth is already wondering if he will become king naturally or if he will have to take the throne through dark deeds.The split reaction shows a difference in character between the two men. Macbeth, overcome with ambition, can think only of his chance at power, while Banquo is much more concerned about how the witches might deceive him into committing evil deeds.

To change speed you need to have an?

Speed is the ratio of distance traveled over a given duration of time. 

That is, speed = distance/time

To change the speed of an object, the object will need an acceleration (or deceleration) and this is only possible by application of force. According to Newton's First Law of motion, a body requires an external force to cause a change in its state of motion (from rest to motion or change in motion for an already moving body). According to Newton's Second Law of Motion, the force is a product of mass of the body and acceleration of the body. Hence, the speed can be changed only by application of an external force, which will generate an acceleration of the body. If the force is in the same direction as the motion, the acceleration will increase the object's speed. If the force is in the opposite direction (or has a component that resists the motion), the acceleration will resist the motion and the speed of the object will change.

Hope this helps.