Some differential equations can be solved exactly, and some cannot. Sometimes one can only be estimated, and a computer program can do this very fast. Although they may seem overly-complicated to someone who has not studied differential equations before, the people who use differential equations tell us that they would not be able to figure important things out without them. Most scientists and engineers (as well as mathematicians) take at least one course in differential equations while in college. Some mathematicians devote their career to investigating differential equations that are difficult to solve.
Differential equations are used in many fields of science since they describe real things:
Windhoek
Windhoek () is the capital city of Namibia. It has a population of 230,000 people. Windhoek is the trade center for sheep skins. The area was controlled by Germany in 1885. It became the capital of the German colony, German South-West Africa, in 1892. During World War I, Windhoek was captured by South Africa. It was the capital of South West Africa (Namibia) under South African control until the independence of Namibia in 1990.
Windhoek has a semi-desert climate.
Windhoek is known to be among the cleanest cities in Africa.
Boiling tube
A boiling tube is a large tube made of glass, which is used in laboratory to strongly heat substances. A boiling tube is a scaled-up test tube, but larger in size. This larger size allows substances to boil freely inside a boiling tube.
Boiling tubes can also be used as a replacement for test tubes specially when a larger volume is desired.
Boiling tubes are commonly made from Pyrex glass which can tolerate high temperatures.
1982 Atlantic hurricane season
The 1982 Atlantic hurricane season was a yearly event of tropical cyclones in the Atlantic Ocean. The season officially started on June 1, 1982, and ended on November 30, 1982. Six named storms formed during the season, along with 2 hurricanes.
While most of the storms were usually weak, the most deadliest storm of the season was Tropical Storm Beryl which killed 115 people while moving across the Caribbean Sea.
A tropical depression formed off western Cuba on June 1 from an group of organized thunderstorms. It moved slowly northeastward through the Gulf of Mexico, and strengthened into Tropical Storm Alberto on June 3. Alberto travelled usually northeast on an unpredictable course and for a hort time, strengthened to a Category 1 hurricane, one of the earliest hurricanes of June. Alberto then quickly weakened back into a tropical storm, moved back to the west, and died near the Florida Keys, Florida, on June 6.
Though the storm never made landfall, Alberto killed 23 people in Cuba from heavy flooding. Southern Florida saw fair rainfall, with a maximum of 16.47 inches occurring in Tavernier.
The first subtropical storm of the season formed in the eastern part of the Gulf of Mexico on June 18, and took an almost straight path to the northeast for its whole life. It crossed the Florida peninsula that night, causing an issue of several severe thunderstorm and tornado warnings. The storm continued, crossing the Outer Banks of North Carolina, and kept its strength until June 20 when it became extratropical near Newfoundland.
Subtropical Storm One caused three deaths in Florida, sank a fishing ship off the coast of North Carolina, and caused $10 million in damage (1982 USD, $20 million 2005 USD).
Beryl became a tropical storm on August 28 while southeast of the Cape Verde islands. The tropical storm travelled slowly west-northwest, while once coming close to hurricane strength. While midway across the Atlantic on September 2, it weakened to a tropical depression. The depression continued west until its circulation collapsed on September 6, just north of the Windward Islands. Beryl killed 115 people in the Cape Verde islands. Though the Cape Verde islands are usually not affected by hurricanes, another tropical storm, Fran, hit the islands in 1984, killing 31 people.
A non-tropical low formed on September 8 in the Gulf of Mexico. It moved west, and the next day it became into a subtropical depression. Under the control of another low pressure system, the depression turned north, and after slowly becoming better organized it strengthened into Tropical Storm Chris on September 10. The storm had maximum sustained winds of 65 mph (100 km/h) before moving onto land near Sabine Pass in Louisiana. Chris continued to move inland until it died over central Arkansas on September 13.
Just before Chris made landfall, as many as 6,500 people moved out from southern Louisiana, while many oil workers moved inland. Chris caused a total of $2 million (1982 USD) in damages.
Debby began as a tropical wave that collapsed shortly after leaving the coast of Africa. The wave travelled across the Atlantic, and became a tropical depression off the northern coast of Haiti on September 13. The depression turned north and strengthened into a tropical storm and then a hurricane. Hurricane Debby moved north-northeast, affecting Bermuda with tropical storm-force winds. It continued strengthening as it moved north, peaking at 135 mph (220 km/h). Tropical storm-force winds were also recorded at Cape Race in Newfoundland when Debby passed by on September 18. The storm began to speed up and weaken over the colder waters of the north Atlantic. Debby combined itself with a strong non-tropical system over the British Isles on September 20.
The tropical disturbance that eventually formed Debby dropped heavy rainfall across Puerto Rico, peaking at 12.86 inches in the southwestern part of the island. Debby was known to cause only minor damages that was related to the storm.
A tropical wave formed off the coast of Africa on September 23. The westeren part of the wave grew bigger and was called Tropical Depression Six on September 30. The depression strengthened, and made a sharp turn on October 1. An Air Force plane found 40 mph winds with a pressure of 1003 mbar and the depression was given the name Ernesto. A second Air Force plane on October 2 found 70 mph winds with a pressure of 997 mbar. By October 3, Ernesto was no longer recognized after combining itself with an extratropical low. Ernesto never came near land and caused no damages.
Ouagadougou
Ouagadougou (, is the capital of Burkina Faso. It is also the country's biggest city. In Ouagadougou, people mainly make clothing and food. Ouagadougou's mayor is chosen every five years. Ouagadougou is near the equator. It is always warm. In Ouagadougou, people speak French. Ouagadougou is one of the poorest cities in Africa. Almost 70% of its people can not read or write but the city has ten universities.
Informal trade is widespread in the streets.
Ouagadougou is twinned with following cities:
Venetian language
The Venetian language (in Venetian: "") is a Romance language.
It was the language once spoken in the Republic of Venice.
In the present day, it is spoken in the Italian regions of Veneto and Friuli-Venezia Giulia, in Slovenia and in Croatia. It is also spoken in Brazil (Rio Grande do Sul and Santa Catarina states) and Mexico (town of Chipilo) by the descendants of Italian immigrants.
Yamoussoukro
Yamoussoukro is the capital city of Côte d'Ivoire (The Ivory Coast). About 200,000 people live in this city. It is not the biggest city in Côte d'Ivoire. Abidjan is the biggest city in Côte d'Ivoire, and it is where most of the country's money comes from. Yamoussoukro became the capital in 1983. Abidjan was the capital before that.