2015IYPT(28届)赛题(中英文)陆建隆.doc

2015 IYPT(28届)赛题（中英文）
 1.Packing
The fraction of space occupied by granular particlesdepends on their shape. Pour non-spherical particles such as rice, matches, or M&M’scandies into a box. How do characteristics like coordination number,orientational order, or the random close packing fraction depend on therelevant parameters?
1、填充物
颗粒状的粒子根据它们的形状会填满部分空间。将一些非球状粒子如：米粒、火柴、或M&M’s巧克力豆倒入盒中。像配位数、取向序、随机密堆积率这样的特性取决于哪些相关参数？

2.Plume of Smoke
If a burning candle is covered by atransparent glass, the flame extinguishes and a steady upward stream of smokeis produced. Investigate the plume of smoke at various magnifications.
2、烟缕
燃烧的蜡烛被透明玻璃容器所遮罩，火焰熄灭后会产生一股稳定的上升烟雾。研究在不同放大倍数下的烟缕。

3.Artificial Muscle
Attach a polymer fishing line to an electric drill andapply tension to the line. As it twists, the fibre will form tight coils in aspring-like arrangement. Apply heat to the coils to permanently fix thatspring-like shape. When you apply heat again, the coil will contract.Investigate this ‘artificial muscle’.
3、人造肌肉
将一根化纤鱼线缠绕在电钻上并系紧。当电钻旋转时，纤维将会以弹簧状排列紧紧地缠绕。加热线圈使其永久固定成弹簧状。当你再次加热时，线圈就会收缩。研究这种“人造肌肉”。

4.Liquid Film Motor
Form a soap film on a flat frame. Put thefilm in an electric field parallel to the film surface and pass an electriccurrent through the film. The film rotates in its plane. Investigate andexplain the phenomenon.

4、液膜电机
在一个平面框架内形成一个肥皂膜。将其放入一个方向与膜表面平行的电场内，并让一股电流通过这薄膜。这个薄膜会在其平面内会发生转动。研究并解释这个现象。

5.Two Balloons
Two rubber balloons are partiallyinflated with air and connected together by a hose with a valve. It is foundthat depending on initial balloon volumes, the air can flow in differentdirections. Investigate this phenomenon.
5、两只气球
向两只橡胶气球里充气使其部分膨胀并用一根带有阀门的软管连接在一起。会发现气体流动方向会根据初始气球体积变化。研究这个现象。

6.Magnus Glider
Glue the bottoms of two light cups together to make aglider. Wind an elastic band around the centre and hold the free end thatremains. While holding the glider, stretch the free end of the elastic band andthen release the glider. Investigate its motion.
6、马格努斯滑翔机
将两个轻质的杯子底部粘在一起制成一个滑翔机。在其中心位置卷绕一根弹性橡皮筋并握住其自由端。握住这个滑翔机，利用橡皮筋的弹力将滑翔机弹出去。研究这个运动。

7.Shaded Pole
Place a non-ferromagnetic metal disk over anelectromagnet powered by an AC supply. The disk will be repelled, but notrotated. However, if a non-ferromagnetic metal sheet is partially insertedbetween the electromagnet and the disk, the disk will rotate. Investigate thephenomenon.

7、屏蔽磁极
将一个非铁磁性金属盘放在一个由交流电源供电的电磁体上。圆盘将被排斥但不会旋转。然而，如果将一个非铁磁性金属板部分插在电磁体和金属盘之间，圆盘则会旋转。研究这个现象。

8.Sugar and Salt
When a container with a layer of sugarwater placed above a layer of salt water is illuminated, a distinctive fingering pattern may be seen in the projectedshadow. Investigate the phenomenon and its dependence on the relevantparameters.
8、糖和盐
当一个盐水层在上，糖水层在下的容器被光照射时，会在投射阴影区看到一个特别的指进图案。研究这个现象和相关因素。

9.Hovercraft
A simple model hovercraft can be built using a CD anda balloon filled with air attached via a tube. Exiting air can lift the devicemaking it float over a surface with low friction. Investigate how the relevantparameters influence the time of the 'low-friction' state.
9、气垫船
将一张CD和一个充满气的气球通过一根管子相连接，可以制成一个简易气垫船模型。释放气体可以抬高装置使其以较低的摩擦力在平面上滑行。研究相关因素是如何影响“低摩擦”状态的时间。

10.Singing Blades of Grass
It is possible to produce a sound byblowing across a blade of grass, a paper strip or similar. Investigate thiseffect.
10、草片的震鸣（草笛）
我们可以通过吹草叶，纸条或类似的东西产生声音。研究这个效应。

11.Cat’s Whisker
The first semiconductor diodes, widely used in crystalradios, consisted of a thin wire that lightly touched a crystal of asemiconducting material (e.g. galena). Build your own ‘cat’s-whisker’ diode andinvestigate its electrical properties.
11、卡特晶体
第一代半导体二极管，由一根很细的金属丝和一个半导体材料晶体（如硫化铅）构成，两者轻轻接触，被广泛的应用于晶体收音机中。自制一个“卡特晶体”二极管并研究它的电学性质。

12.Thick Lens
A bottle filled with a liquid can work asa lens. Arguably, such a bottle is dangerous if left on a table on a sunny day.Can one use such a ‘lens’ to scorch a surface?
12、厚透镜
一个装满水的瓶子可以作为一个透镜。可以说，这样一个瓶子如果在晴天放置在桌子上是危险的。人们可以用这样一个“透镜”烧焦一个平面吗？

13.Magnetic Pendulum
Make a light pendulum with a small magnet at the freeend. An adjacent electromagnet connected to an AC power source of a much higherfrequency than the natural frequency of the pendulum can lead to undampedoscillations with various amplitudes. Study and explain the phenomenon.
13、磁性摆
制作一个轻摆，并在其自由端放置一个小磁铁。旁边放置一个由交流电提供能源的电磁体，交流电的频率比摆的固有频率要高很多。电磁体可以使摆以不同的振幅进行无阻尼摆动。研究并解释这个现象。

14.Circle of Light
When a laser beam is aimed at a wire, acircle of light can be observed on a screen perpendicular to the wire. Explainthis phenomenon and investigate how it depends on the relevant parameters.
14、环绕的光
当一束激光照射在一根金属丝上时，可以在垂直于金属丝的屏幕上观察到一个光圈。解释这个现象并研究相关参数对其影响。

15.Moving Brush
A brush may start moving when placed on avibrating horizontal surface. Investigate the motion.
15、移动的刷子
一把放置在振动的水平面上的刷子会产生移动。研究这个运动。

16.Wet and Dark
Clothes can look darker or change colourwhen they get wet. Investigate the phenomenon.
16、潮湿与暗色
衣服变潮湿会看上去更暗或者会改变颜色。研究这个现象。

17.Coffee Cup
Physicists like drinking coffee, however walkingbetween laboratories with a cup of coffee can be problematic. Investigate howthe shape of the cup, speed of walking and other parameters affect thelikelihood of coffee being spilt while walking.
17、咖啡杯
物理学家喜欢喝咖啡，但是端着杯咖啡在实验室间走动可能会有麻烦。研究杯子的形状、走路的速度以及其他因素将如何影响在行走时杯子洒出咖啡的可能性。