校赛题目更正版正式发布 （中文翻译仅供参考）

1. Invent Yourself

Construct a passive device that will provide safe landing for an uncooked hen’s egg when dropped onto a hard surface from a fixed height of 2.5 m. The device must fall together with the egg. What is the smallest size of the device you can achieve?   

自己发明

建造一个无源装置——能为从2.5米固定高度坠向坚硬地面的生鸡蛋提供安全着陆，装置必须与鸡蛋一起坠落，你能实现的装置的最小尺寸是多少？

2.Air horn

A simple airhorn can be constructed by stretching a balloon over the opening of a small container or cup with a tube through the other end (see Figure). Blowing through a small hole in the side of the container can produce a sound. Investigate how relevant parameters affect the sound. 

一个简单的汽笛可以这样制造：用一根穿过一只小型容器（或杯子）底部的管子（如图）拉伸位于容器（或杯子）开口处的气膜。经由在容器侧壁处的小孔，鼓风可以产生一个声音。探讨相关参数如何影响声音。

3.Single Lens Telescope

      A telescope can be built using a single lens, provided that a small aperture is used instead of an eyepiece. How do the parameters of the lens and the hole influence the image (e.g. magnification, sharpness and brightness)? 

      一架望远镜可只用一枚透镜制作，如果小光圈被用于替代目镜，那么透镜参数和孔会如何影响图像（如放大率、清晰度和亮度）？

4. Fast Chain

A chain consisting of wooden blocks inclined relative to the vertical and connected by two threads (see Figure) is suspended vertically and then released. Compared to free fall, the chain falls faster when it is dropped onto a horizontal surface. Explain this phenomenon and investigate how the relevant parameters affect the motion. 

一个链条由若干木棍稍微和水平相比有一定角度，然后用两跟细线链接，如图所示。和自由落体相比，这个链条掉落在一个水平地面上的时候会下落的更快一点。请分析是怎么回事？相关变量是如何影响这个下落过程的？

5.Pulling Glasses

Apart Put a thin layer of water between two sheets of glass and try to separate them. Investigate the parameters affecting the required force. 

把两个平面玻璃之间放水，然后玻璃就能粘在一起。这样再尝试把这两个玻璃分开，分析哪些变量会影响这个分开玻璃的力。

6.Hair Hygrometer

A simple hygrometer can be built using human hair. Investigate its accuracy and response time as a function of relevant parameters. 

我们用头发就能制作一个简单的湿度计。分析它的精确程度，以及反应时间。

7.Torsion Gyroscope

Fasten the axis of a wheel to a vertical thread that has a certain torsional resistance (see Figure). Twist the thread, spin the wheel, and release it. Investigate the dynamics of this system.

将轮轴固定于具有一定扭转阻力的竖直线上（见图），扭转绳子，旋转轮子并释放它，探讨此系统的动力。

8.Boiled Egg

Suggest non-invasive methods to detect the degree to which a hen’s egg is cooked by boiling. Investigate the sensitivity of your methods. 

建议用非损伤的方法来检测鸡蛋煮熟的程度。探讨你方法的敏感度。