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 2.5m. The device must fall together with the egg. What is the smallest size of the device you can achieve?

2. Balloon Airhorn

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. Blowing through a small hole in the side of the container can produce a sound. Investigate how relevant parameters affect the sound.

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)?

4. Magnetic Hills

5. Leidenfrost Stars

6. Fast Chain

A chain consisting of wooden blocks inclined relative to the vertical and connected by two threads 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.

7. Spiral Waves

Spiral waves and other types of wave patterns may occur on a thin liquid film flowing over a rotating disk. Investigate these wave patterns.

8. Visualising Density

9. Ball in a Tube

A sealed transparent tube is filled with a liquid and contains a small ball. The tube is inclined and its lower end is attached to a motor such that the tube traces a conical surface. Investigate the motion of the ball as a function of relevant parameters.

10. Pulling Glasses Apart

11. Hair Hygrometer

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

12. Torsion Gyroscope

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

13. Resonating Glass

A wine glass partially filled with liquid will resonate when exposed to the sound from a loudspeaker. Investigate how the phenomenon depends on various parameters.

14. Gee-Haw Whammy Diddle

A gee-haw whammy diddle is a mechanical toy consisting of a simple wooden stick and a second stick that is made up of a series of notches with a propeller at its end. When the wooden stick is pulled over the notches, the propeller starts to rotate. Explain this phenomenon and investigate the relevant parameters.

15. 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.

16. Metronome Synchronization

A number of mechanical metronomes standing next to each other and set at random initial phases under certain conditions reach synchronous behavior in a matter of minutes. Investigate the phenomenon.

17. Vacuum Bazooka

※藍色字體表示第九屆競賽用題目，黑色字體則為2017國際賽題目，縮排內容為題目敘述。