Problems for the 31st IYPT 2018
1.Invent Yourlf
Construct a simple ismograph that amplifies a local disturbance by mechanical, optical or electrical methods. Determine the typical respon curve of your device and investigate the parameters of the damping constant. What is the maximum amplification that you can achieve?
1、自己发明
构造简单的地震仪，通过机械，光学或电气方法放大局部扰动。 确定设备的典型响应曲线，并探究阻尼常数的参数。 你可以实现的最大放大倍数是多少？
2.Colour of Powders
If a coloured material is ground to a powder, in some cas the resulting powder may have a different colour to that of the original material. Investigate how the degree of grinding affects the apparent colour of the powder.
2、粉末的颜色
如果将有色材料研磨成粉末，则在某些情况下，所得到的粉末可能具有与原始材料不同的颜色。 探究研磨程度如何影响粉末的表观颜色。
3.Dancing Coin
wherever
Take a strongly cooled bottle and put a coin on its neck.Over time you will hear a noi and e movements of the coin. Explain this phenomenon and investigate how the relevant parameters affect the dance.
3、跳舞的硬币
拿一个强烈冷却的瓶子，把一个硬币放在瓶颈处。过一会儿你会听到一个噪音，并看到硬币运动。 解释这个现象，并探究相关参数如何影响舞蹈。
4.Heron's Fountain
Construct a Heron’s fountain and explain how it works.Investigate how the relevant para
meters affect the height of the water jet.
4、海伦的喷泉
名校课堂答案
构造海伦喷泉并解释它的形成原理。探究相关参数如何影响水柱的高度。
美国大选时间5.Drinking Straw
When a drinking straw is placed in a glass of carbonated drink, it can ri up, sometimes toppling over the edge of the glass. Investigate and explain the motion of the straw and determine the conditions under which the straw will topple.
5、吸管
当将一根吸管放在一杯碳酸饮料中时，它可能会升高，有时会也翻倒在杯沿上。研究和解释吸管的动作，确定吸管倒伏的条件。
6.Ring Oiler
第57届格莱美An oiled horizontal cylindrical shaft rotates around its axis at constant speed. Make a ring from a cardboard disc with the inner diameter roughly twice the diameter of the shaft and put the ring on the shaft. Depending on the tilt of the ring, it can travel along the shaft in either direction.Investigate the phenomenon.
6、环形润滑器
涂有油的水平圆柱轴以恒定速度绕其轴线旋转。 用纸板制成一个my jolly sailor bold怎样挽回丈夫圆环，内径大约是轴直径的两倍，并将环放在轴上。依赖于环的倾斜，它可以沿轴向某一方向行进。研究此现象。
7.Conical Piles
Non-adhesive granular materials can be poured such that they form a cone-like pile. Investigate the parameters that affect the formation of the cone and the angle it makes with the ground.
哈利波特 mp37、锥形桩
用非粘性颗粒材料可以浇筑形成圆锥形桩。研究影响锥体形成的参数及其与地面的角度。
8.Cusps in a Cylinder
A horizontal cylinder is partially filled with a viscous fluid.When the cylinder is rotated aroundits axis, unusual fluid behaviour can be obrved, such as cusp-like shapes on the walls of the cylinder. Investigate the phenomenon.
8、圆筒中的尖形
水平圆筒部分地填充有粘性流体。当圆柱体绕轴旋转时，可以观察到异常的流体行为，例如圆筒壁上出现尖形。研究此现象。
9.Candle in Water
Add some weight to a candle such that it barely floats in water. As the candle burns, it may continue to float. Investigate and explain this phenomenon.
9、水中的蜡烛
给蜡烛添加一些重量，使其在水中几乎不上浮。 当蜡烛燃烧时，它可能会持续上浮。 研究
并解释这个现象。
10.Tesla Valve
A Tesla valve is afixed-geometry, passive, one-direction valve. A Tesla valve offers a resistance to flow that is much greater in one direction compared to the other. Create such a Tesla valve and investigate its relevant parameters.
10、特斯拉阀门
特斯拉阀门是几何形状固定、被动式单向阀。 特斯拉阀门在一个方向给流体提供的阻力比其它方向要大得多。 创建一个特斯拉阀门并研究其相关参数。
11.Azimuthal-Radial Pendulum
Fix one end of a horizontal elastic rod to a rigid stand. Support the other end of the rod with a taut string to avoid vertical deflection and suspend a bob from it on another string (e figure). In the resulting pendulum the radial oscillations (parallel to the rod) can spon
taneously convert into azimuthal oscillations (perpendicular to the rod) and vice versa. Investigate the phenomenon.
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11、方位径向摆
将水平弹性杆的一端固定到刚性支架上。 用绷紧的绳子支撑杆的另一端，以避免垂直偏转，并将物体悬挂在另一根绳上（见图）。 在产生的摆中，径向振荡（平行于杆）可以自发地变换振荡方位（垂直于杆），反之亦然。研究此现象。12.Curie Point Engine
Make a nickel disc that can rotate freely around its axis.Place a magnet near the edge of the discand heat this side of it. The disc starts to rotate. Investigate the parameters affecting the rotation and optimize the design for a steady motion.
12、居里点发动机
制作可绕其轴线自由旋转的镍盘。在靠近圆盘边缘处放置一个磁铁，并加热这一侧。 圆盘开始旋转。 探究影响旋转的参数，并优化设计使其稳定运动。
13.Weighing Time
历届奥运会主题曲It is commonly known that an hourglass changes its weight(as measured by a scale) while flowing. Investigate this phenomenon.
13、时间计量
众所周知，沙漏的重量会随沙子的流动而改变（按比例度量）。研究这种现象。
14.Radiant Lantern
When taking a picture of a glowing lantern at night, a number of rays emanating from the centre of the lantern may appear in the pictures. Explain and investigate this phenomenon.
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