On behalf of the Academic Com-mittee of the 43rd International Physics Olympiad it is our plea-sure to welcome you to Estonia and to wish you all success in the

forthcoming competition. Physics is a uni-versal language, understandable independent of geographic location. Although Estonia is a small country, it has made valuable contri-butions to the physical science, in particular in the fields of astronomy, laser optics and nuclear magnetic resonance. The Interna-tional Physics Olympiad is an outstanding opportunity to promote physics and physical education. Estonia has been participating in IPhOs since 1992, and since then we have enjoyed the hospitality of 21 countries. We very much hope to return to you on this oc-

casion some of the warmth we ourselves have enjoyed all over the world. For some time we have been working hard to make the coming Olympiad as memorable for you as possible. In the competition, we have tried to balance the problems to include both simple and re-ally challenging questions, rich in physical content, and relatively simple mathemati-cally. We also hope that besides solving the problems this is a chance for you to find new friends, have a good time, and learn a bit about our country and the people living here. Welcome to Estonia!

NEWSLETTER – July 17th 2012

Issue nO.3www.ipho2012.ee/newsletter

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The Examination Day vol1

Dear friends!

Jaak Kikas & Jaan KaldaChair and Co-chair of the IPhO 2012

The first seconds of the Opening Ceremony

say cheese in estonian - “hernesupp”

Physicists are rock stars! Austrian delegation

estonian folk dancers called “Viisuke”

Trummers

Media interviewing contestants

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The importance of the opening ceremony is to create the first impression of the organizing country of IPhO. It started with contemporary dance to awaken our senses.

After this wake-up perfor-mance the speaker of the Estonian parliament, Ene Ergma, came on stage to wish the contestants the best and said that the rainy weather during IPhO was not bad at all, it helped to cool us down.

The President of the IPhO, Hans Jordens, said that organizing such an event as IPhO could not be done overnight. He added: “IPhO is like a water-shed – there is life before the Olympiad and another afterwards. And the two are not alike.“ The presi-dent promised that participants would like Tartu for its historic centre and would certainly remember it for the theorical and experimental tests.

The Head of the Academic Committee of the IPhO 2012, Jaan Kikas, hoped that visitors would also have a chance to learn about Estonia and peo-ple living here.

After all the greetings, it was time to say wel-come to every participating country and to the start of a serious competition.

Read more online: www.ipho2012.ee/newsletterText: Brenda Raunste

students from Iran.

While the students were on their way to Tartu, the leaders and ob-servers gathered in Radisson Blu Hotel Olümpia to prepare tomor-row’s theory problems. Correct-ing lasted until late evening and then the heads of the delegations continued translating the tests. Text: Saile Mägi

First International Board Meeting

Opening Ceremony

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Estonia has altogether 1500 islands and Saaremaa is the biggest of them. The island is a favourite tourist destination in summer, es-

pecially during the Midsummer Eve celebra-tions, when the waiting queues of car for the ferry are 4-5 km long. Who wouldn’t want to spend the year’s “whitest” night on a beauti-ful island among junipers and windmills?

The island’ remoteness from the mainland makes its outlook unique. Some Saarmaa vil-lages still have stone fences and houses with thatched roofs. There are also windmills that give the island a little bit of a dutch feeling. Rich flora and fauna and hundreds of thou-sands of migrated birds add beauty to the landscape of the island.

The symbol of the island is juniper – a tree, that you probably won’t encounter on the mainland. But in Saaremaa you can see it growing in the wild and also buy souvenirs made of it. They say that a spoon made of ju-niper makes your food powerful.

The most famous attraction on Saaremaa is definitely Kaali lake, which is in Europe’s biggest meteorite crater. Kaali crater is 16 metres deep and has a diameter of 110 metres.

If you have had enough of nature, then head to the island’s only town – Kuressaare. A late 13th century fortress dominates the town.

Text: Saile Mägi

Windmill on the island of saaremaa.

Fishing in the morning fog.

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Tartu Adventure Park.

Not far from the center of Tartu is a park where you can test the effects of gravity and your flexibility by climb-ing some trees. Along the different adventure

tracks, some trees are as high as 12 meters from the ground and you can slide down from them on a wire 300 metres long. Besides hanging on to wires up in the trees, you can also ride a bicycle and snowboard. Remem-ber – balance and patience are the keys that help you to succeed and survive the challeng-es in the park. But if you do happen to fall off the wire or lose your footing on a branch, don’t worry – you won’t fall, because no one is allowed to take part in the adventures with-out a safety harness.Text: Saile Mägi

Happy Birthday!

Julio CarlosChorro Huezo

LorenzEberhardt

MasaoNinomiya

MátéVigh

Adventure Park in Tartu

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Delegates

Feynman’s Corner

Tightrope walking (solution)There are several reasons. To begin with, thightrope walkers use rods which bend down: this lowers the height of their centre of mass. Second, a long rod increases their mo-ment of inertia. Together with his rod, a tight-rope walker can be considered as a reversed physical pendulum. The period of such a pendulum is increased when the distance be-tween the centre of mass and rotation axis is decreased, or when the moment of inertia is increased. For a reversed pendulum (ie. when the centre of mass is above the rotation axis), the period can be considerd as a characteris-tic falling time. With a longer falling time, it is easier to fix a lost balance. Third, long rod helps restoring the balance. Suppose the centre of mass of a tightrope walker (together

Through the Earth (solution)The geographical coordinates of Tartu – of your examination point, to be exact, are 58°23’20’’ N, 26°41’45’’ E. Hence those for the antipodal point are 58°23’20’’ S, 153°18’15’’ W – this is somewhere in South-Pacific – a bit of a wet place to get out J. As to the duration of travel, it takes about 42 min-utes – notably less than your trip from Tallinn to Tartu. You can find the solution here: http://hyperphysics.phy-astr.gsu.edu/hbase/mechanics/earthole.html

Waves on a beachHave you noticed that waves always run to-wards the beach, regardless of the direction of the wind. Why?

with the rope) has shifted rightwards from the rope. In order to restore the balance, he needs a returning (counter-clockwise) torque of the gravity field. To this end, the centre of mass needs to be shifted temporarily leftwards, for which a horizontal external force is needed. The rope can provide such a force if those parts of the tightrope walker which are far-ther away from the rope - such as his upper body or the rod - are turned clockwise: during angular acceleration, the rest of the body tries to rotate counter-clockwise (due to the con-servation of angular momentum) but cannot: the rope prevents the motion of legs with a horizontal leftwards force. The rod performs here more efficiently than the upper part of the body, because its average distance from the rope is larger.