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.

5．极为不易打湿东西的水

把一个装满肥皂水的盘子放在扬声器或者震动台上，当它震动的时候，它有可能会把一小滴液滴留在上面很长时间，解释并研究这一现象。

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.

7．热水喷泉

用热水部分装填一个莫尔吸量管。用你的大拇指盖住其上端并倒置，可观察到从尖部喷出的水喷泉。请研究决定水喷泉高度的参量，并改变它们以获得喷泉最大的高度。

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.

8．磁力小火车

两个扁圆柱形磁铁与一个柱状的电池两端相接，当这个体系放在铜线圈内部且与铜接触的时候，它会开始运动。解释这个现象并且研究相关参量怎么影响火车的速度和功率。

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.

10．光环

让一个液体喷向一个平面，当接触点被激光照明的时候，可观测到环绕水柱的光环。研究这个光环和相关参量对整个系统的影响。

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.

15．非接触千分尺

请利用一个激光笔发明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。

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?

17．疯狂的手提箱

当一个人拉着一个两轮的旅行箱的时候，在某些时候旅行箱会很剧烈地左右摆最终倾覆。研究这个现象。一个人可否通过不同的装箱方法来抵制或激化这种现象吗？