IYPT2016题目及中文翻译.docx

2016年国际青年物理学家锦标赛（IYPT）题目
1.真实的随机数
真随机数是一种稀缺而珍贵的资源。设计并制造、测试一个产生真随机数的装置。研究在干扰下，多长的随机数产生是安全的。
2.滞后摆
摆是由摆和重物组成的，当摆的支点开始绕水平圆周运动，摆开始做一个半径更小的圆周运动，研究在特定情况下的摆的运动和稳定时的轨迹。
3.声透镜
菲涅耳透镜是一种具有同心螺纹的透镜，声波也有类似于此的原理，设计并制造声学透镜，研究诸如放大率等相关参数。
4.超级蹦蹦球
将一个弹性很好的球向两块平板之间扔出，这个球开始弹来弹去，在某些情况甚至能够回到你的手中，研究球的运动轨迹以及影响运动的参数，包括板的方向。
5.疏水性水滴之谜
将一个装有肥皂水的盘子放到扬声器或者震动台上。当震动的时候，可能会出现一些小水滴长时间的保持在盘子上，解释并研究这一现象。
6.电致蜂巢
将一个金属针垂直的放到金属板上，将一些油滴到金属板上，通直流高压时会观察到在液体表面会产生类似于细胞的结构，解释并研究这一现象。
7.沸泉
将滴定管中装一部分水，用拇指盖住其上端并且盗跖滴定管，可以观察到有喷泉产生。研究影响喷泉高度的参量，并且研究在何时喷泉能够达到最大高度。
8.磁力列车
用纽扣磁铁把柱状的电池两端相连，将其被放到一个铜线圈中，当其与铜线圈接触时，“磁力列车”开始运动。解释这个现象并且研究相关参量如何影响火车的速度和功率。
9.水波
用一个竖直振动的水平圆筒产生水波，当改变激励振幅或者频率时，水波会表现出远离或者靠近圆筒的样子，研究一下这个现象。
10.光之环
将液体喷到一个平面上，将激光照到平面与液体接触处，可以看到环绕在旁边的光环，研究这个光环，并确定其与什么系统参量有关。
11.在disc（光盘）上翻滚！
如果将一个轻的滚动的物体（例如环，圆盘，球）放到水平放置的旋转的光盘上，物体可以开始运动而不离开光盘。解释不同参量是如何影响运动的。
12.范德堡测量法
只要一个样品无洞并有边界，那么这个材料的电阻率就可以使用范德堡方法被测量出，与其形状无关。什么情况下也能适用这一方法？如果这个样品是有洞的，研究并解释测量的方法。
13.纸之力
用两本相似的书，让一些页互相交错而放，并且把两本书尽可能的靠近在一起，用手拉两本书的书脊使两本书分开。研究能把书分开所用的最小作用力是多少。
14.敏感的火焰
一种可燃性气体（如丙烷）从一个气嘴里垂直的喷出穿过金属网格（二者距离约为5cm左右）。可燃气体被点燃并在金属网格上方形成火焰。在某些情况下，火焰会对声音极其灵敏。研究这个现象和相关参量的影响。
15.非接触式测量器
使用一个激光笔设计并制造一个做的光学仪器，使其可以不接触地测量一个玻璃片的厚度、折射率以及其他属性。
16.涡旋
一个板子部分地放在水里，沿着这个板子的法线方向拉动，就会在水的表面形成一对漩涡。在一定情况下，这些漩涡将会沿着水面做长时间传播。研究相关参量对水涡运动和稳定性的影响。
17.疯狂旅行箱
当一个人拉着一个两轮的旅行箱的时候，在某些情况，旅行箱会很剧烈地摇摆以至于倾覆。研究这个现象。能否通过不同的装载方式来减弱或增强这种现象？

附英文版：
The problem for the 29th IYPT
1．Invent yourself
Truly random numbers are a very valuable and rare resource. Design, produce, and test a mechanical device for producing random numbers. Analyse to what extent the randomness produced is safe against ering tamp
2．Lagging Pendulum
A pendulum consists of a strong thread and a bob. When the pivot of the pendulum starts moving along a horizontal circumference the bob starts tracing a circle which can have a smaller radius, under certain conditions. Investigate the motion and stable trajectories of the bob.
3．Acoustic Lens
Fresnel lenses with concentric rings are widely used in optical applications, however a similar principle can be used to focus acoustic waves. Design and produce an acoustic lens and investigate its properties, such as amplification, as a function of relevant parameters.
4．Super Ball
Throw a highly elastic ball into the space between two plates. The ball starts bouncing and under some circumstances can even be projected back to you. Investigate the motion of the ball and parameters influencing the motion, including the orientation of the plates.
5．Ultrahydrophobic Water
Set a dish filled with soapy water onto a loudspeaker or other vibrator. When it oscillates, it is possible to hold small droplets on its surface for a long time. Explain and investigate the phenomenon.
6．Electric Honeycomb
Set a vertically oriented steel needle over a horizontal metallic plate. Place some oil onto the plate. If you apply constant high voltage between the needle and the plate, a cell structure appears on the surface of the liquid. Explain and investigate this phenomenon.
7．Hot Water Fountain
Partially fill a Mohr pipette with hot water. Cover the top of the pipette with your thumb. Turn the tip upwards and observe the fountain exiting the tip. Investigate the parameters describing the height of the fountain, and optimize them to get the maximum height.
8．Magnetic Train
Button magnets are attached to both ends of a small cylindrical battery. When placed in a copper coil such that the magnets contact the coil, this "train" starts to move. Explain the phenomenon and investigate how relevant parameters affect the train's speed and power.
9．Water Wave
Generate a water wave with a vertically oscillating horizontal cylinder. When varying the excitation frequency and/or amplitude, the water seems to drift away from or towards the cylinder. Investigate the phenomenon.
10．Light Rings
Let a liquid jet fall onto a surface. If the contact point is illuminated by a laser beam, rings of light around the jet can be observed (see Figure). Investigate the light rings and determine how they depend on relevant parameters of the whole system.
11．Rolling on a Disc
If you put a light rolling object (e.g a ring, a disc, or a sphere) on a horizontal rotating disc, it may start moving without being expelled from the disc. Explain how different types of motion depend on the relevant parameters.
12．Van der Pauw Method
It is known that conductivity of a material can be measured independently of the sample shape, as long as the sample has one border (no holes). To what extent can such a method be applied? Investigate and explain such measurements if the sample has holes.
13．Paper Vice
Take two similar paperback books and interleave a few pages at a time. Push the books together. Hold the two books by their spines and try to pull them apart. Investigate the parameters that set the limits of being able to separate the books.
14．Sensitive Flame
A combustible gas (e.g. propane) streams vertically out of a fine nozzle and then through a fine metallic mesh at a distance of about 5 cm. The gas is lit and produces a flame above the mesh. Under some circumstances, this flame reacts very sensitively to sound. Investigate the phenomenon and the relevant parameters.
15．Contactless Calliper
Invent and construct an optical device that uses a laser pointer and allows contactless determination of thickness, refractive index, and other properties of a glass sheet.
16．Frisbee Vortices
When a vertical plate is partially submerged in water and pulled in a direction normal to the plate, a pair of vortices is created in the surface of the water. Under certain conditions, these vortices travel along the surface for a long distance. Investigate the parameters influencing the motion and stability of these vortices.
17．Crazy Suitcase
When one pulls along a two wheeled suitcase, it can under certain circumstances wobble so strongly from side to side that it can turn over. Investigate this phenomenon. Can one suppress or intensify the effect by varied packing of the luggage?