An athlete uses physics to shatter world records - Asaf Bar-Yosef

Sportista koji koristi fiziku da sruši svetske rekorde - Asaf Bar-Jozef (Asaf Bar-Yosef)

Prevodilac: Anca Dimovska Lektor: Miloš Milosavljević

In the early 1960s,

Ranih šezdesetih,

Dick Fosbury tried his hand at almost every sport,

Dik Fozberi se oprobao u skoro svim sportovima,

but never excelled at anything,

ali se ni u čemu nije isticao

until, at the age of 16, he turned to the high jump.

dok se, u šesnaestoj godini, niije okrenuo skoku uvis.

But when he couldn't compete against

Ali pošto nije uspevao da parira

the strong athletes at his college

jakim sportistima na koledžu

using the standard high jump techniques of the time,

koristeći standardne tehnike tog vremena za skok uvis,

Fosbury tried to jump a different way: backwards.

Fozberi je probao da skače drugačije: unazad.

Instead of jumping with his face towards the bar,

Umesto da skače licem prema letvici,

bringing each leg over in the

prebacujući noge preko

traditional straddle method,

tradicionalnom metodom opkoračenja,

he jumped with his back towards the bar.

skakao je leđima okrenutim prema letvici.

Fosbury improved his record by over half a foot,

Fozberi je poboljšao svoj rekord za više od 15 cm

and left his coaches amazed

i oduševio trenere

by this strange new style of high jumping.

ovim neobičnim novim stilom skoka uvis.

During the next few years,

Tokom sledećih par godina.

Fosbury perfected his high jump style,

Fozberi je usavršio svoj stil skoka,

won the U.S. National trials,

osvojio nacionalno izborno takmičenje u SAD-u

and assured his place in the 1968 Olympics in Mexico.

i osigurao svoje mesto na Olimpijadi u Meksiku 1968.

In the Olympic Games, Fosbury amazed the world

Na Olimpijskim igrama, Fozberi je zadivio svet

with his new technique, winning a gold metal

svojom novom tehnikom, osvojivši zlatnu medalju

with an Olympic record leap of 2.24 meters.

sa olimpijskim rekordom od 2,24 m.

By the next Olympic Games,

Do sledećih Olimpijskih igara,

almost all of the competing of high jumpers

skoro svi takmičari u skoku uvis

had adopted what came to be known as

su usvojili tehniku koja je postala poznata kao

the Fosbury Flop.

Fozberi flop.

What's the secret behind the technique?

U čemu je tajna ove tehnike?

It lies in a physics concept

Ona leži u fizičkom pojmu

called the center of mass.

zvanom centar mase.

For every object,

Za svaki predmet

we can locate the average position of all of its mass

možemo da nađemo centralnu tačku celokupne njegove mase,

by taking into account how the mass

tako što uzmemo u obzir kako je ta masa

is spread around the object.

u njemu raspoređena.

For instance, the center of mass

Na primer, centar mase

of a flat, rectangular object of uniform density

ravnog pravougaonog predmeta ujednačene gustine

will be in the intersection of both diagonals,

biće na preseku dijagonala,

in equal distance from each corner.

na podjednakoj udaljenosti od svakog ugla.

We can find the center of mass for other objects

Možemo da nađemo centar mase i za druge predmete

by similar calculations,

pomoću sličnih proračuna

or by finding the object's balancing point,

ili nalaženjem tačke ravnoteže predmeta,

which lies right underneath its center of mass.

koja se nalazi odmah ispod njegovog centra mase.

Try balancing a broom by holding it

Probajte da držite metlu tako što je uhvatite

and slowly bringing your hands together until they meet.

i polako pomerate ruke jednu prema drugoj dok se ne sretnu.

This balancing point lies right underneath

Tačka ravnoteže se nalazi tačno ispod

the broom's center of mass.

centra mase metle.

We humans also have a center of mass.

Mi, ljudi, takođe imamo centar mase.

When most people stand up,

Kod većine ljudi, kada stoje,

their center of mass is around the belly,

ovaj centar je oko stomaka,

but what happens to your center of mass

ali šta se dešava sa vašim centrom mase

when you lift your hands in the air?

kada podignete ruke uvis?

Your center of mass moves upwards.

Vaš centar mase se pomera nagore.

It moves all the time as you move through the day,

Stalno se pomera kako se vi pomerate u toku dana,

based on how your body is positioned.

zavisno od pozicije vašeg tela.

It can even move outside of your body.

Čak može da se pomeri i van vašeg tela.

When you bend forward, your center of mass

Kada se nagnete napred, vaš centar mase

is located below your bent belly

se nalazi ispod vašeg povijenog stomaka.

in a place where there is no mass at all.

na mestu gde uopšte ne postoji masa.

Weird to think about, but that's the average position

Čudno je kad se pomisli, ali to je centralna tačka

of all your mass.

vaše celokupne mase.

Many objects' center of mass

Centar mase mnogih stvari

are outside their bodies.

je van njihovog tela.

Think of doughnuts or boomerangs.

Pomislite na krofne ili bumerange.

Now look at the Fosbury Flop, and follow the position

Sad pogledajte Fozeri flop i pratite poziciju

of the center of mass of the jumper.

centra mase skakača.

The jumper runs very fast,

Skakač trči jako brzo,

so he can divert his horizontal velocity

da bi mogao da preusmeri svoje horizontalno ubrzanje

to vertical velocity, and jumps.

u vertikalno, i da skoči.

Wait for it...there.

Obratite pažnju...evo ga.

Look at the jumper's center of mass

Pogledajte skakačev centar mase

as his body bends backward.

dok mu se telo naginje unazad.

It's below the bar.

Nalazi se ispod letvice.

That is the secret behind the jump.

U ovome je tajna ovog skoka.

With the old, pre-Fosbury techniques,

Sa starom tehnikom pre Fozberijeve,

the jumper had to apply enough force

skakač je morao da uloži dovoljno snage

to lift his center of mass above the bar

da podigne centar mase iznad letvice

by a few inches in order to clear it.

za nekoliko centimentara da bi je izbegao.

The Fosbury Flopper doesn't have to do that.

Fozberi floper ne mora to da radi.

The genius of the Fosbury Flop is that the jumper

Genijalnost Fozberi flopa je u tome što skakač

can apply the same amount of force,

može da uloži istu količinu snage,

but raise his body much higher than before.

ali da pritom izdigne telo više nego pre.

That means he can raise the bar so high

Ovo znači da može da podigne letvicu tako visoko

that even when his center of mass

da čak i kad njegov centar mase

can't go any higher, his arching body can.

ne može da se podigne više, njegovo izvijeno telo može.

Fosbury's technique brought

Fozberijeva tehnika je donela

the high jump to new heights

nove visine skoku uvis

by splitting the jumper's body

tako što je odvojila telo skakača

away from his center of mass,

od njegovog centra mase,

giving it that much more room

dajući više prostora

to clear higher and higher bars.

da se preskoče sve veće i veće visine.

So the Fosbury Flop may be sports history's

Tako da je Fozberi flop možda jedini veliki

only great leap forward,

skok unapred u istoriji sporta,

that is also a great leap backward.

koji je istovremeno i skok unazad.