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Sharpen Your General Knowledge
Shamim Ansary:
What Is Thunder?
When electricity is given off through lightning, it heats the air in its path. This heating makes the air expand quickly and often violently.
The molecules of heated air fly around in all directions and collide with cooler, distant air. This collision sets up a “wave†of noisy, rumbling air called thunder.
Shamim Ansary:
How Are Fossils Dated and What Are the Two Methods of Dating Fossils?
The first is known as relative dating.
By determining the age of the surrounding rock, scientists can give an approximate age to the fossils therein.
Rocks are dated by their distance from the surface, with older rocks generally deeper from the surface.
Using the data from other fossils found in the same rock stratum can also be used to give an approximate date to a new sample.
The second method is known as absolute dating.
Absolute dating relies on the known rates of radioactive decay within rocks.
By measuring the ratio between the radioactive forms of an element like uranium-238 to its nonradioactive, “decayed†form, scientists can determine when the rock formed, because that would be when the radioactive isotope was acquired.
Amino acids also convert gradually from one form (the lefthanded) to another (right-handed) after an organism dies and so may be used as a method of dating some fossils.
Shamim Ansary:
Does Canada Have a President and a Congress Like the United States?
Canada does not have a president and a congress like the United States.
The Canadians are led by a prime minister, who is the leader of the political party that wins the most seats in its parliament.
The parliament of Canada consists of the Senate and the House of Commons.
The 104 senators are appointed by the 10 provincial governments, and they may serve until they are 75 years old.
The 301 members of the House of Commons are elected by the people and serve up to 5 years.
Shamim Ansary:
Why Did Indians In Old Movies Put Their Ears to the Ground to Find Out If the Cavalry Was Coming?
Depending on variables like the size of the troop and the type of terrain, the Indians may have been able to hear the troops from quite a distance.
There are many factors involved in the seismology of such a phenomenon, and only individual experiments would determine how much energy would be coupled into the ground and how far the sound would be transmitted.
For example, what is the strength of the source? Are all the forces pushing on the earth together at the same time, or is it random noise?
If the approaching army is on horses, it is probably random noise, while soldiers marching in step would present a different set of factors.
Another important variable is the kind of terrain.
Hard rock would not carry the sound very far, because a running horse does not move the ground much, so not much seismic energy is coupled into the ground.
On the other hand, if there is a river basin with consolidated sediment, and the cavalry is on the road upriver, with the Indians around the corner on the same sedimentary formation, the soil would be a good conduit, and they could hear for quite a way.
If the soil is wet, however, the energy of the horses’ hooves might go into deforming the ground, rather than vibrating it.
A listener along a railroad track might have an advantage.
Seismic energy travels along a linear body, and a train is much heavier than a horse, visibly bending the track when it passes over it.
Therefore, the track would carry sound well, almost like a vibrating wire.
Shamim Ansary:
Who Invented Money and Why?
Money is defined as anything that can be accepted as payment for goods or services. It is also used as payment of debt.
money us 20 dollar bill
Early uses of money began with the bartering of goods almost 100,000 years ago. Goods were exchanged for other goods and this developed the commodity money system. Commodity money is money whose value comes from the object itself. In other words, objects that have value in themselves as well as for use as money.
One of the first forms of currency is The shekel. It was was originally both a unit of currency and a unit of weight and originated from Mesopotamia around 3000 BC. Many cultures in Asia and Africa used shell money which was usually the rare cowry shell.
Eventually, commodity money was replaced by Representative money. Representative money is what most of us are familiar with and are token that represents a fixed monetary value. Examples of Representative money are coins, bank notes or bills, cheques and bank drafts.
The word “money†comes from from a temple of Hera, which sits on on Capitoline, one of Rome’s seven hills. Money was invented to serve three functions, as a medium of exchange, unit of account, and store of value.
Today, the exchange of money and commodity drives the world economy, and as they say on TV, makes the world go round.
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