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

Translator: Hafizh Alfarisi Reviewer: Athira Rizka

In the early 1960s,

Pada awal 1960, Dick Fosbury mencoba hampir semua olahraga,

Dick Fosbury tried his hand at almost every sport,

but never excelled at anything,

tetapi tak pernah menguasai satu pun.

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

Sampai umur 16 tahun, dia beralih ke lompat tinggi.

But when he couldn't compete against

Namun, saat dia tak dapat bersaing dengan para atlet kuat di kampusnya

the strong athletes at his college

using the standard high jump techniques of the time,

dengan teknik lompat tinggi biasa yang umum digunakan,

Fosbury tried to jump a different way: backwards.

Fosbury mencoba melompat dengan cara berbeda: ke belakang.

Daripada melompat dengan wajah menghadap mistar,

Instead of jumping with his face towards the bar,

bringing each leg over in the

sehingga tiap kaki terangkat dalam gaya guling tradisional,

traditional straddle method,

he jumped with his back towards the bar.

dia melompat dengan punggung menghadap mistar.

Fosbury improved his record by over half a foot,

Fosbury menaikkan rekornya sebanyak 15 cm

and left his coaches amazed

dan pelatihnya kagum oleh gaya lompat tinggi yang asing ini.

by this strange new style of high jumping.

Selama tahun-tahun berikutnya, Fosbury menyempurnakan gaya lompat tingginya,

During the next few years,

Fosbury perfected his high jump style,

won the U.S. National trials,

memenangkan Olimpiade Uji Coba AS,

and assured his place in the 1968 Olympics in Mexico.

dan memastikan tempatnya di Olimpiade Meksiko 1968.

Di olimpiade ini, Fosbury mencengangkan dunia

In the Olympic Games, Fosbury amazed the world

with his new technique, winning a gold metal

lewat teknik barunya dan memenangkan medali emas

with an Olympic record leap of 2.24 meters.

dengan rekor lompatan Olimpiade setinggi 2,24 meter.

By the next Olympic Games,

Di Olimpiade selanjutnya, hampir semua pelompat tinggi yang bersaing

almost all of the competing of high jumpers

had adopted what came to be known as

mengikuti gaya yang dikenal dengan nama Fosbury Flop.

the Fosbury Flop.

What's the secret behind the technique?

Apa rahasia teknik ini?

It lies in a physics concept

Teknik ini bertumpu pada konsep fisika bernama pusat massa.

called the center of mass.

For every object,

Pada setiap objek, kita bisa menentukan posisi rerata dari semua massanya

we can locate the average position of all of its mass

by taking into account how the mass

dengan mempertimbangkan cara massa disebarkan ke sekitar objek.

is spread around the object.

Misalnya, pusat massa benda persegi rata dengan kepadatan sama

For instance, the center of mass

of a flat, rectangular object of uniform density

punya titik temu di kedua diagonal, dengan jarak seimbang dari tiap sudut.

will be in the intersection of both diagonals,

in equal distance from each corner.

Kita bisa menemukan pusat massa untuk tiap objek dengan penghitungan serupa,

We can find the center of mass for other objects

by similar calculations,

atau dengan menemukan titik keseimbangan objek,

or by finding the object's balancing point,

which lies right underneath its center of mass.

yang terletak tepat di bawah pusat massanya.

Try balancing a broom by holding it

Coba seimbangkan sapu dengan memegangnya

and slowly bringing your hands together until they meet.

dan dekatkan kedua tanganmu perlahan sampai mereka bertemu.

This balancing point lies right underneath

Titik keseimbangan ini terletak tepat di bawah pusat massa sapu.

the broom's center of mass.

We humans also have a center of mass.

Manusia juga punya pusat massa.

When most people stand up,

Saat umumnya orang berdiri, pusat massa mereka di sekitar perut.

their center of mass is around the belly,

but what happens to your center of mass

Namun, apa jadinya pusat massamu ketika kau mengangkat tangan ke atas?

when you lift your hands in the air?

Your center of mass moves upwards.

Pusat massamu bergerak ke atas.

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

Ia terus bergerak saat kau bergerak sepanjang hari,

based on how your body is positioned.

berdasarkan cara tubuhmu diposisikan.

It can even move outside of your body.

Pusat massa bahkan bergerak di luar tubuhmu.

When you bend forward, your center of mass

Saat kau membungkuk ke depan, pusat massamu

is located below your bent belly

terletak di bawah perut bungkukmu di tempat yang tak ada massa sama sekali.

in a place where there is no mass at all.

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

Memang terdengar aneh, tetapi itulah rata-rata posisi semua massamu.

of all your mass.

Many objects' center of mass

Ada banyak objek dengan pusat massa di luar fisiknya.

are outside their bodies.

Bayangkan donat atau bumerang.

Think of doughnuts or boomerangs.

Now look at the Fosbury Flop, and follow the position

Sekarang lihat Fosbury flop dan perhatikan letak pusat massa pelompat ini.

of the center of mass of the jumper.

The jumper runs very fast,

Pelompat berlari sangat cepat, agar dia bisa mengalihkan kecepatan horizontalnya

so he can divert his horizontal velocity

to vertical velocity, and jumps.

ke kecepatan vertikal, dan melompat.

Wait for it...there.

Tunggu sejenak. Itu dia.

Look at the jumper's center of mass

Lihat pusat massa pelompat begitu badannya membungkuk ke belakang.

as his body bends backward.

It's below the bar.

Pusatnya di bawah mistar.

That is the secret behind the jump.

Itulah rahasia lompatannya.

Pada teknik lama, sebelum Fosbury, pelompat harus memakai cukup tenaga

With the old, pre-Fosbury techniques,

the jumper had to apply enough force

to lift his center of mass above the bar

untuk mengangkat pusat massanya ke atas mistar

beberapa inci agar bisa melewatinya.

by a few inches in order to clear it.

The Fosbury Flopper doesn't have to do that.

Pengguna Fosbury flop tak harus melakukannya.

The genius of the Fosbury Flop is that the jumper

Pintarnya Fosbury flop adalah pelompat bisa memakai jumlah tenaga yang sama,

can apply the same amount of force,

but raise his body much higher than before.

tetapi mengangkat tubuhnya lebih tinggi dari sebelumnya.

That means he can raise the bar so high

Berarti, dia bisa menaikkan mistar lebih tinggi.

that even when his center of mass

Bahkan meski pusat massanya tak bisa naik lebih tinggi,

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

badan melengkungnya sanggup.

Fosbury's technique brought

Teknik Fosbury membawa lompat tinggi ke ketinggian baru

the high jump to new heights

dengan memisah badan pelompat jauh dari pusat massanya,

by splitting the jumper's body

away from his center of mass,

giving it that much more room

sehingga ada lebih banyak ruang untuk melewati mistar yang lebih tinggi.

to clear higher and higher bars.

So the Fosbury Flop may be sports history's

Fosbury flop mungkin lompatan ke depan terhebat sepanjang sejarah olahraga,

only great leap forward,

that is also a great leap backward.

yang juga lompatan ke belakang terhebat.