March 31st

The Eiffel tower was inaugurated on 31 March 1889, and opened on 6 May.

March 30th

In 1909, the Queensboro Bridge opens, linking Manhattan and Queens.

March 29th

In 1461, Wars of the Roses: Battle of Towton Edward of York defeats Queen Margaret to become King Edward IV of England.

March 28th

In 1930, Constantinople and Angora change their names to Istanbul and Ankara.

March 27th

In 1976, the first 4.6 miles of the Washington Metro subway system opens.

March 26th

In 1958, the United States Army launches Explorer 3.

March 25th

In 1409, the Council of Pisa opens.

March 24th

In 1603, Tokugawa Ieyasu is granted the title of shogun from Emperor Go-Yozei, and establishes the Tokugawa Shogunate in Edo, Japan.

March 23rd

In 1956, Pakistan becomes the first Islamic republic in the world. (Republic Day in Pakistan)

March 22nd

In 1993, the Intel Corporation ships the first Pentium chips (80586), featuring a 60 MHz clock speed, 100+ MIPS, and a 64 bit data path.

March 21st

In 1965, ranger program: NASA launches Ranger 9 which is the last in a series of unmanned lunar space probes.

March 20th

In 1916, Albert Einstein publishes his general theory of relativity.

March 19th

In 1918, the U.S. Congress establishes time zones and approves daylight saving time.

March 18th

In 1871, Declaration of the Paris Commune; President of the French Republic, Adolphe Thiers, orders evacuation of Paris.

March 17th

In 180, Marcus Aurelius dies leaving Commodus the sole emperor of the Roman Empire.

March 16th

In 1968, General Motors produced its 100 millionth automobile, the Oldsmobile Toronado.

March 15th

In 44 BC, Julius Caesar, Dictator of the Roman Republic, is stabbed to death by Marcus Junius Brutus, Gaius Cassius Longinus, Decimus Junius Brutus and several other Roman senators on the Ides of March.

March 14th

In 1489, the Queen of Cyprus, Catherine Cornaro, sells her kingdom to Venice.

March 13th

In 1639, Harvard College is named for clergyman John Harvard.

March 12th

In 1918, Moscow becomes the capital of Russia again after Saint Petersburg held this status for 215 years.

March 11th

In 1867, the first performance of Don Carlos by Giuseppe Verdi takes place in Paris.
And today, in 2011, an earthquake measuring 9.1 in magnitude strikes 130 km (80 miles) east of Sendai, Japan, triggering a tsunami.

March 10th

In 1814, Napoleon I of France is defeated at the Battle of Laon in France.

March 9th

In 1842, the first documented discovery of gold in California occurs at Rancho San Francisco, six years before the California Gold Rush.

March 8th

In 1618, Johannes Kepler discovered the third law of planetary motion.

March 7th

In 1799, Napoleon Bonaparte captures Jaffa in Palestine and his troops proceed to kill more than 2,000 Albanian captives.

March 6th

In 1869, Dmitri Mendeleev presents the first periodic table to the Russian Chemical Society.

March 5th

In 1946, Winston Churchill uses the phrase "Iron Curtain" in his speech at Westminster College, Missouri.

March 4th

In 1493, Explorer Christopher Columbus arrives back in Lisbon, Portugal, aboard his ship Niña from his voyage to what is now The Bahamas and other islands in the Caribbean.

360

In terms of electromagnetism, one watt is the rate at which work is done when one ampere (A) of current flows through an electrical potential difference of one volt (V).

Also, in terms of classical mechanics, one watt is the rate at which work is done when an object's velocity is held constant at one meter per second against constant opposing force of one newton.

When a light bulb with a power rating of 100W is turned on for one hour, the energy used is 100 watt-hours (W h), 0.1 kilowatt-hour, or 360 kJ.

2.3901 x 10^-4

1 joule is equivalent to 2.3901 x 10^-4 kilocalorie.

It is dimensionally correct to say that 1 joule equals 1 newton metre (1 J = 1 N m = 1 kg m^2 s^−2).

10,000

One hectare is equivalent to 10,000 square meter. This is because prefix "hect" means 100, and squared 100 is 10,000.

The metric system of measure was first given a legal basis in 1795 by the French Revolutionary government. The law of 18 Germinal, Year III (7 April 1795) defined five units of measure:

The metre for length
The are (100 m2) for area [of land]
The st re (1 m3) for volume of firewood
The litre (1 dm3) for volumes of liquid
The gram for mass