How taking a bath led to Archimedes' principle - Mark Salata

Kako je kupanje dovelo do Arhimedovog principa - Mark Salata

1,641,681 views

2012-09-06 ・ TED-Ed


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How taking a bath led to Archimedes' principle - Mark Salata

Kako je kupanje dovelo do Arhimedovog principa - Mark Salata

1,641,681 views ・ 2012-09-06

TED-Ed


Please double-click on the English subtitles below to play the video.

Prevodilac: Mile Živković Lektor: Tatjana Jevdjic
00:14
Some of the best opportunities to learn
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Neke od najboljih prilika za učenje
00:16
are the moments in which we are perplexed.
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su trenuci kada smo zbunjeni.
00:18
Those moments in which you begin to wonder and question.
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Oni trenuci kada se pitate i zapitkujete.
00:21
These moments have happened throughout history.
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Ovi trenuci dešavali su se tokom cele istorije
00:23
and have led to some truly amazing discoveries.
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i doveli su do nekih zaista zapanjujućih otkrića.
00:25
Take this story, for example.
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Na primer, uzmite ovu priču.
00:27
There once was a fellow named Archimedes.
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Jednom je postojao čovek zvani Arhimed.
00:29
He was born in 287 B.C. in the city of Syracuse in Sicily.
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Rodio se 287. godine pre nove ere, u Sirakuzi na Siciliji.
00:32
He was a Greek mathematician, physicist, engineer,
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Bio je grčki matematičar, fizičar, inženjer
00:35
inventor, and astronomer.
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izumitelj i astronom.
00:37
One day, Archimedes was summoned by the king of Sicily
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Jednog dana, Arhimeda je zvao kralj Sicilije
00:40
to investigate if he had been cheated by a goldsmith.
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da ispita da li ga je prevario zlatar.
00:43
The king said he had given a goldsmith the exact amount of gold
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Kralj je rekao da je zlataru dao tačnu količinu zlata
00:46
needed to make a crown.
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koja je potrebna da se napravi kruna.
00:48
However, when the crown was ready, the king suspected that the goldsmith cheated
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Ipak, kada je kruna bila gotova, kralj je posumnjao da ga je zlatar prevario
00:52
and slipped some silver into the crown,
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i u krunu ubacio malo srebra,
00:54
keeping some of the gold for himself.
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tako zadržavši nešto zlata za sebe.
00:56
The king asked Archimedes to solve the problem.
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Kralj je pitao Arhimeda da reši problem.
00:59
But there was a catch: he couldn't do any damage to the crown.
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Ali postojala je kvaka - nije smeo da ošteti krunu.
01:04
One day, while taking his bath,
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Jednog dana, dok se kupao,
01:06
Archimedes noticed that the water level in the bathtub rose
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Arhimed je primetio da se nivo vode u kadi dizao
01:09
and overflowed as he immersed himself into the tub.
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i da se kada prelivala kada bi uronio u nju.
01:12
He suddenly realized that how much water was displaced
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Iznenada je shvatio da to koliko vode izađe
01:15
depended on how much of his body was immersed.
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zavisi od toga koji deo njegovog tela je uronjen.
01:18
This discovery excited him so much that he jumped out of the tub
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Ovo otkriće toliko ga je uzbudilo da je iskočio iz kade
01:21
and ran through the streets naked, shouting "Eureka!"
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i go potrčao kroz ulice vičući: "Eureka!"
01:24
Which comes from the ancient Greek meaning "I found it."
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Što na starogrčkom znači: "Pronašao sam."
01:27
What did he find?
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Šta je on to pronašao?
01:29
Well, he found a way to solve the king's problem.
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Pa, pronašao je način da reši kraljev problem.
01:31
You see, Archimedes needed to check the crown's density
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Vidite, Arhimed je trebalo da proveri gustinu krune
01:34
to see if it was the same as the density of pure gold.
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kako bi video da li je iste gustine kao čisto zlato.
01:37
Density is a measure of an object's mass divided by its volume.
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Gustina je mera mase objekta podeljena se njegovom zapreminom.
01:40
Pure gold is very dense, while silver is less dense.
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Čisto zlato je veoma gusto, dok je srebro manje gusto.
01:43
So if there was silver in the crown, it would be less dense than if it were made of pure gold.
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Ako je u kruni bilo srebra, ona bila manje gusta nego da je sačinjena od čistog zlata.
01:48
But no matter what it was made of, the crown would be the same shape,
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Ali bez obzira od čega je napravljena, kruna bi imala isti oblik,
01:51
which means the same volume.
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što znači istu zapreminu.
01:53
So if Archimedes could measure the mass of the crown first,
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Dakle, ako bi Arhimed prvo izmerio masu krune,
01:55
and then measure its volume,
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i onda izmerio njenu zapreminu,
01:57
he could find out how dense it was.
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mogao bi da otkrije koliko je bila gusta.
01:59
But it is not easy to measure a crown's volume - it has an irregular shape,
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Ali nije lako izmeriti zapreminu krune - ona ima nepravilan oblik,
02:02
that's different from a simple box or ball.
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koji je drugačiji od jednostavne kutije ili lopte.
02:04
You can't measure its size and multiply like you might for other shapes.
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Ne možete joj izmeriti veličinu i to samo pomnožiti, kao kod drugih oblika.
02:08
The solution, Archimedes realized,
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Arhimed je shvatio da je rešenje u tome
02:11
was to give the crown a bath.
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da se kruna okupa.
02:13
by placing it in water and seeing how much water was displaced,
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Tako što bi je stavio u vodu i video koliko vode izlazi,
02:16
he could measure the volume,
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mogao bi da izmeri zapreminu
02:18
and he'd calculate the density of the crown.
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i izračunao bi gustinu krune.
02:21
If the crown was less dense than pure gold,
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Ako je kruna manje gustine nego čisto zlato,
02:23
then the goldsmith most definitely cheated the king.
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onda je zlatar sasvim sigurno prevario kralja.
02:26
When Archimedes went back to the king and did his test,
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Kada se Arhimed vratio kod kralja i uradio ovaj test,
02:29
the story says, he found that the goldsmith had indeed cheated the king,
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po priči, otkrio je da je zlatar zaista prevario kralja,
02:33
and slipped some silver in. These days,
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i ubacio nešto srebra. U današnje vreme,
02:36
using the way an object displaces water to measure volume is called
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merenje zapremine pomoću količine vode koju objekat izbaci
02:39
Archimedes' principle. The next time you take a bath,
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zove se Arhimedov princip. Sledeći put kada se budete kupali
02:42
you can see Archimedes' principle in action,
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možete videti Arhimedov princip na delu
02:45
and maybe you'll have a genius idea of your own.
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i možda se i vama javi neka genijalna ideja.
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