2023IYPT全球青年物理學家錦標賽賽題翻譯！

自1988 年起，一年一度的全球青年物理學家錦標賽從(cong) 一個(ge) 蘇聯地方性俄語的競賽逐漸成長為(wei) 一個(ge) 全球最大最具聲望的國際物理競賽之一。

在2022年CUPT參賽隊員緊張備賽之時，2023年IYPT賽題已悄然發布！本文將題目中英文及相應分析一並呈遞給大家，希望能對接下來一年的PTer有所幫助。

以下是賽題圖片版及文字版：

36屆國際青年物理學家競賽賽題

01Fractal Fingers 分形手指

The effect of fractal fingering can be observed if a droplet of an ink-alcohol mixture is deposited onto diluted acrylic paint. How are the geometry and dynamics of the fingers influenced by relevant parameters?

如果將一滴油墨和酒精的混合物滴在稀釋的丙烯酸塗料上，就可以觀察到分形手指效應。手指的幾何形狀和動力學將如何受相關(guan) 參數影響？

02Oscillating Sphere 振蕩球

A light sphere with a conducting surface is suspended from a thin wire. When the sphere is rotated about its vertical axis (thereby twisting the wire) and then released, it starts to oscillate. Investigate how the presence of a magnetic field affects the motion.

一個(ge) 表麵導電的輕球懸掛在一根細導線上。當球繞著其垂直軸旋轉（從(cong) 而扭轉導線）並釋放，它會(hui) 開始振蕩。研究磁場的存在會(hui) 如何影響這一運動。

03Siren 汽笛

If you direct an air flow onto a rotating disk with holes, a sound may be heard. Explain this phenomenon and investigate how the sound characteristics depend on the relevant parameters.

如果你把氣流導向有孔的旋轉圓盤，就會(hui) 聽到聲音。解釋這一現象，並研究聲音特性如何依賴於(yu) 相關(guan) 參數。

04Coloured Line 彩色線

When a compact disc or DVD is illuminated with light coming from a filament lamp in such a way that only rays with large angles of incidence are selected, a clear green line can be observed. The colour varies upon slightly changing the angle of the disc. Explain and investigate this phenomenon.

當隻選用白熾燈光中入射角較大的光照射光盤或DVD時，會(hui) 出現一條明顯的綠色線。光盤的角度稍有改變，顏色就會(hui) 發生變化。解釋並研究此現象。

05Whistling Mesh 口哨網

When a stream of water hits a rigid metal mesh within a range of angles, a whistling tone may be heard. Investigate how the properties of the mesh, stream and angle affect the characteristics of the sound produced.

當水流以一定角度衝(chong) 擊剛性金屬網時，可能聽到口哨聲。研究金屬網、水流的性質及角度大小將如何影響聲音的特征。

06、Magnetic-Mechanical Oscillator 磁機械振蕩器

Secure the lower ends of two identical leaf springs to a non-magnetic base and attach magnets to the upper ends such that they repel and are free to move. Investigate how the movement of the springs depends on relevant parameters.

將兩(liang) 個(ge) 相同的葉片彈簧下端固定在一個(ge) 無磁基座上，並將兩(liang) 塊磁鐵吸附在彈簧上端，使他們(men) 相互排斥且可以自由移動。研究彈簧的運動如何取決(jue) 於(yu) 相關(guan) 參數。

07Faraday Waves 法拉第波

A droplet of less viscous liquid floating in a bath of a more viscous liquid develops surprising wave-like patterns when the entire system is set into vertical oscillation. Investigate this phenomenon and the parameters relevant to the production of stable patterns.

當整個(ge) 係統處於(yu) 垂直振蕩狀態時，一滴低粘度液體(ti) 漂浮在一團粘性較強液體(ti) 中，會(hui) 產(chan) 生令人驚訝的波形圖案。研究此現象以及與(yu) 形成穩定圖案有關(guan) 的參數。

08 Euler’s Pendulum 歐拉擺

Take a thick plate of non-magnetic material and fix a neodymium magnet on top of it. Suspend a magnetic rod (which can be assembled from cylindrical neodymium magnets) underneath it. Deflect the rod so that it touches the plate only with highest edge and release it. Study the motion of such a pendulum under various conditions.

取一塊厚的、由非磁性材料製成的板，並在其上麵固定一個(ge) 釹磁鐵。在板的下方懸掛一根磁性杆（可以由多塊圓柱形釹磁鐵組裝製成）。使杆偏轉至它隻有最頂部的邊沿接觸到板，然後將其釋放。研究這種擺在各種條件下的運動。

09Oscillating Screw 振蕩的螺絲(si)

When placed on its side on a ramp and released, a screw may experience growing oscillations as it travels down the ramp. Investigate how the motion of the screw, as well as the growth of these oscillations depend on the relevant parameters.

當把一顆螺絲(si) 側(ce) 放在斜麵上並釋放時，螺絲(si) 可能會(hui) 在沿著斜麵向下運動時產(chan) 生越來越大的振蕩。研究螺絲(si) 的運動以及這種振蕩的增長如何取決(jue) 於(yu) 相關(guan) 參數。

10Upstream Flow 逆流而上的運動

Sprinkle light particles on a water surface. Then allow a water stream to be incident on the surface from a small height. Under certain conditions, the particles may begin to move up the stream. Investigate and explain this phenomenon.

在水麵上撒上輕質顆粒，然後讓水流從(cong) 很小的高度入射水麵。在一定條件下，微粒可能會(hui) 沿水流向上運動。研究並解釋這一現象。

11Ball on Ferrite Rod 鐵氧體(ti) 棒上的球

A ferrite rod is placed at the bottom end of a vertical tube. Apply an ac voltage, of a frequency of the same order as the natural frequency of the rod, to a fine wire coil wrapped around its lower end. When a ball is placed on top of the rod, it will start to bounce. Explain and investigate this phenomenon.

鐵氧體(ti) 棒放置在垂直管的底端。施加一個(ge) 交流電壓，頻率與(yu) 棒的固有頻率相同的階數，以細線線圈包裹其下端。當一個(ge) 球放在球杆上時，它就會(hui) 開始反彈。解釋並調查這一現象。

12 Rice Kettlebells 大米壺鈴

Take a vessel and pour some granular material into it, for example, rice. If you dip e.g. a spoon into it, then at a certain depth of immersion, you can lift the vessel and contents by holding the spoon. Explain this phenomenon and explore the relevant parameters of the system.

向一個(ge) 容器中倒入一些顆粒狀物質（例如大米）。如果把勺子等物體(ti) 浸入顆粒狀物質中，在一定的浸入深度下，可以通過提起勺子來提起容器和其中的顆粒。解釋這個(ge) 現象並探究係統的相關(guan) 參數。

13 Ponyo’s Heat Tube 波妞的熱管

A glass tube with a sealed top is filled with water and mounted vertically. The bottom end of the tube is immersed in a beaker of water and a short segment of the tube is heated. Investigate and explain the periodic motion of the water and any vapour bubbles observed.

把一個(ge) 頂部密封的玻璃管裝滿水並垂直安裝。把玻璃管的底端浸入裝有水的燒杯中，使玻璃管的一小段被加熱。研究並解釋水和觀察到的氣泡的周期性運動。

14Jet Refraction 射流的折射

A vertical jet can be refracted when passing through an inclined sieve with a fine mesh. Propose a law for such refraction and investigate relevant parameters.

垂直射流通過帶有細網的斜篩時會(hui) 發生折射。為(wei) 這種折射提出一個(ge) 定律並研究相關(guan) 參數的影響。

15 Pancake Rotation 煎餅的旋轉

Place a few balls in a round container. If you move the container around a vertical axis, the balls can move codirectionally with the movement of the container, or they can move in the opposite direction. Explain this phenomenon and investigate how the direction of movement depends on relevant parameters.

將幾個(ge) 球放在一個(ge) 圓形容器中。如果繞一個(ge) 豎直軸移動容器，球可以與(yu) 容器運動方向同向移動，也可以向容器運動方向的反方向運動。解釋這個(ge) 現象並研究運動方向如何取決(jue) 於(yu) 相關(guan) 參數。

16Thermoacoustic Engine 熱聲發動機

A piston placed in the open end of a horizontal test tube which has its other end partially filled with steel wool may oscillate when the closed end is heated up. Investigate the phenomenon and determine the efficiency of this engine.

把一個(ge) 活塞放在水平放置的試管的開口端，試管的封閉端則用鋼絲(si) 絨部分填充。當試管的封閉端被加熱時，活塞可能會(hui) 振動。研究這個(ge) 現象並確定這個(ge) 發動機的效率。

17Arrester Bed 沙地

A sand-filled lane results in the dissipation of the kinetic energy of a moving vehicle. What length is necessary for such an arrester bed to entirely stop a passively moving object (e.g. a ball)? What parameters does the length depend on?

被沙子覆蓋的車道會(hui) 導致行駛車輛的動能損耗。如果要使一個(ge) 被動運動的物體(ti) （如一個(ge) 球）完全停止，這樣的沙地需要多長？長度又取決(jue) 於(yu) 哪些參數？