When we are calculating the resistance of a circuit in parallel, why do we take the formula as reciprocal of 1/R1+1/R2, and for the...

These are the formulas for equivalent resistance: the equivalent resistance of the series circuit with the resistors `R_1` and `R_2` is `R_(eq) = R_1 + R_2` , and the equivalent resistance of the parallel circuit is determined by the formula

`1/R_(eq) = 1/R_1 + 1/R_2`

These formulas come from the way the current flows through the circuits, and are easy to derive:

For the series circuit, the same current must flow through both resistors as the current that flows through the battery. This comes from the law of conservation of charge (current is the rate of the flow of charge.) So, the potential difference supplied by the battery will be split between the two resistors. According to the Ohm's Law, each potential difference is proportional to the resistance:

`U = IR_(eq)` (potential difference supplied by the battery)

`U_1 = IR_1` (potential difference on the first resistor)

`U_2 = IR_2` (potential difference on the second resistor)

`U = U_1 + U_2`

`IR_(eq) = IR_1 + IR_2`

Canceling out the current results in the formula for equivalent resistance of the series circuit: `R_(eq) = R_1 + R_2` .

In the parallel circuit, the current flowing in the circuit will split between the two resistors: `I = I_1 + I_2` . The potential difference, however, must be the same on each resistor and equal to the potential difference supplied by the battery, because the potential difference between the two points does not depend on the path between the two points. Again, the potential difference can be determined from the Ohm's Law:

`U = IR_(eq) = I_1R_1 = I_2R_2`

Expressing currents from here and plugging them in `I = I_1 + I_2` , we find

`U/R_(eq) = U/R_1 + U/R_2`

Canceling out U results in the formula for the equivalent resistance of the parallel circuit:

`1/R_(eq) = 1/R_1 + 1/R_2`.

` `

What is the theme of the poem "Five Ways To Kill A Man" by Edwin Brock?

There are five stanzas to this poem; the main themes of the poem appear to center on the inhumanity of man through succeeding generations and the new threats to life in modern civilization.

Stanza One describes the crucifixion of Christ. The poet describes the sandal-wearing Jewish crowd. The crowing "cock" refers to Peter betraying Christ three times before the rooster crows. Also, Roman soldiers divide the garments of Jesus between themselves (into four shares). However, on the day of his Crucifixion, Jesus is also wearing a seamless tunic/cloak; the soldiers cast lots for this valuable garment because they do not want to divide it. Refer to John 19:23.

To do this properly you require a crowd of people wearing sandals, a cock that crows, a cloak to dissect, a sponge, some vinegar and one man to hammer the nails home.

Stanza Two refers to the medieval era when men still fought with "bows and arrows." The "length of steel" refers to a sword which can pierce through chain-mail hauberks. However, in the later medieval period, armor was often entirely made of steel plates and was much harder to penetrate.

Stanzas Three and Four describe World Wars One and Two. The reference to "gas" signifies chemical warfare, and the "ditches" may be an allusion to trench warfare. Rat infestation in trenches was a greatly feared phenomenon in World War One. The millions of rats which invaded trenches often feasted on rotting corpses and invariably brought disease to already beleaguered troops.

Stanza Four focuses on the bombing of Hiroshima and Nagasaki.

All you then require is an ocean to separate you, two systems of government, a nation's scientists, several factories, a psychopath and land that no-one needs for several years.

The scientists refer to the men who invented and worked on the atomic bomb. As for the psychopath, some experts maintain that it is a reference to President Truman, although others maintain that it is a reference to Hideki Tojo, the imperialistic dictator of Japan, who along with his allies, Germany and Italy, intended to rule the world. The wonderful thing about poetry is that there are often different interpretations based on unique viewpoints.

Stanza Five is the last stanza. After centuries of killing each other, the poet maintains cheekily that he has just been describing "cumbersome ways to kill a man." He argues that a more direct way to kill would be to put someone in the "middle of the twentieth century" and to leave him to the machinations of modern civilization. Thus, the theme of the poem reinforces that the inhumanity of man and the myriad threats to life continue into modernity; danger is not circumscribed by circumstance or time.

What would be dramatically interesting to explore in Lysistrata by Aristophanes? How would one make comedy/tension/impact accessible for the...

Lysistrata is one of the most famous classical Greek comedies, written by Aristophanes and originally performed in 411 BC in Athens. Lysistrata is often performed, as it provides many roles for women and is regarded as a hilarious battle between the sexes. In the plot, Lysistrata famously persuades the women of Greece to withhold sex from their husbands until the men negotiate a peace deal. 

There are a few dramatic elements that can be helpful to focus on while in a rehearsal room with actors. First, the physicality of the play is a big question in a rehearsal room. How do these women move? How do they attract their husbands, but also reject their sexual advances? This conundrum is a fun, open-ended dramatic element that a creative cast must tackle when performing this play. Secondly, can you pull elements from commedia dell'arte? While commedia dell'arte, an Italian art form, was created long after this play was originally performed, many theater companies tackle Lysistrata through Italian clowning. This practice is extremely physical and often funny, and so the acting technique lends itself to modern interpretations of Lysistrata. Finally, how should you tackle the divided Chorus? This Old Comedy technique is exciting and tricky in Lysistrata. A creative team will need to figure out how they portray the divided Chorus. Will men play the Old Men and will women play the Old Women? Will the cast be divided in gender? Will the cast use masks? These are all questions a team can ask themselves and each other. 

What was the first good event in Julie of the Wolves?

The first "good" event in Julie of the Wolves is most definitely when Julie comes upon the wolf pack.  Before this, Julie is in a desperate situation because she has run away from her arranged marriage and has lost her way on the Alaskan tundra.  As soon as Julie spies the wolf pack, she remembers what her father told her about wolves being our "gentle brothers":

Wolves are brotherly. ... They love each other, and if you learn to speak to them, they will love you too.

Remembering her father's wise advice, Julie begins to observe the wolves and try to figure out how she can get them to "love" her.  First, Julie names the wolves.  The leader is Amaroq.  His mate is Silver.  The leader of the wolf pups is Kapu (named after Julie's father, Kapugen).  The sullen outcast is Jello.  

By observing the wolves, Julie learns their behaviors.  A nip on the top of the muzzle means dominance.  Laying belly-up means submission.  Flattened ears are friendly.  Ears pointed forward mean aggression.  Julie uses this knowledge to eventually become part of the pack.

What is the purpose of cellular respiration?

Cellular respiration is the process by which cells consume glucose and oxygen, and break it down into carbon dioxide and water. The process also generates ATP or adenosine triphosphate molecules. These are energy molecules and provide energy for various cellular operations (or functions). Chemically, the process can be written as:

`C_6H_12O_6 + 6O_2 -> 6 CO_2 + 6H_2O + ATP`

The main purpose of this process is to produce energy for maintaining life and other cellular functions. The carbon dioxide produced during the process helps in the greenhouse effect and keeps the planet warm enough for life.

Cellular respiration is complementary to the process of photosynthesis (by which green plants produce glucose molecules and oxygen). Photosynthesis is the process of food production and cellular respiration is the process of food breakdown. Both the processes are necessary for sustenance and propagation of life.  

Hope this helps. 

How much do our individual votes during a presidential election really count?

Our vote, the popular vote, is important during a presidential election. In our political system, each state has a certain number of electoral votes. The number of a state’s electoral votes equals the number of members the state has in both houses of Congress. When we vote for the President and the Vice President, we are voting for electors who will vote for a given candidate in the Electoral College. In most states, the candidate who wins the state’s popular vote gets that state’s entire electoral vote. In order to become President and Vice President, a candidate must get at least 270 electoral votes.

There are other reasons why our vote, the popular vote, is important. In almost every election, the candidate who won the vote in the Electoral College also won the popular vote. While there have been four times when the candidate who won the popular vote didn’t win the election, in the vast majority of elections, the result of the popular vote did determine the winner. Additionally, the percentage of the popular vote a candidate gets can determine if the candidate has a received a mandate from the people to lead the country.

The vote of the people is very important in the election for the President and the Vice President.

What happened to Dave in The Call of the Wild?

The Call of the Wild by Jack London is a short novel published in 1903 set in the Klondike Gold Rush. The story is told from the point of view of a dog, Buck, a domestic St. Bernard and Scottish shepherd mix, who is dognapped at the start of the novel to serve as a sled dog. The story is narrated in the third person, with Buck as the point of view character and the main theme of the story being how both men and animals revert to their primitive natures under duress. 

We are introduced to Dave in Chapter 2. He is part of the nine-dog team run by French Canadians, Perrault and Francois. We are introduced to the team through the eyes of Buck, who observes how the dogs of the team need to behave to survive and who gradually comes to understand the social and power relationships among the dogs. The dog Dave is described as older, hardworking and somewhat of a loner but acts as a mentor to Buck. Buck is normally harnessed just in front of Dave and Dave teaches him about life as a sled dog. In Chapter 3, one of the dogs, Dolly, goes mad and Buck wins a fight with the lead dog Spitz. When Spitz loses, he is killed by the other dogs and Buck becomes the team leader.

In Chapter 4, the team is sold and begins working on the mail run from Dawson to Skagway for an unnamed Scottish half-breed man. Given no rest between mail runs and heavy loads, the dogs begin to weaken and Dave begins whimpering to himself even though nothing is is obviously wrong. At  Cassiar Bar, Dave begins to sicken obviously, and has difficulty walking. The half-breed allows Dave to rest by letting him run beside the sled instead of being harnessed with the other dogs. After a brief rest, Dave catches up with the sled and insists on being let back into his harness despite his weakness:

[Dave] pleaded with his eyes to remain there...[the men] talked of how a dog could break its heart through being denied the work that killed it, and recalled instances they had known, where dogs, too old for the toil, or injured, had died because they were cut out of the traces. Also, they held it a mercy, since Dave was to die anyway, that he should die in the traces, heart-easy and content.

Dave struggles to keep up, but despite his efforts cannot really manage the pace. The team finishes its day's run and goes to sleep. The next morning, Dave is too weak to walk. The driver harnesses the other dogs and moves them and the sled a short distance ahead, leaving Dave behind to howl mournfully. Realizing that Dave will only die a lingering and painful death if abandoned, the driver walks backs and shoots Dave.