Create a non-invasive device that determines the direction of fluid flow inside an opaque pipe. Optimize your device so that you can measure the smallest flow possible.
設計一個可以確定不透明管道內液體流動方向的無損裝置。優化你的裝置以測得盡可能小的流量。
2.Rayleigh Disk 瑞利盤
A disk suspended vertically by a thin thread is placed in an acoustic field. This device can be used to measure the intensity of sound by turning about the axis of the thread. Investigate the accuracy of such a device.
一個圓盤由細線垂直懸掛在聲場中。該裝置可以通過改變細線所在的軸來測量聲音的強度。研究該裝置的精度。
3. Ring on the Rod 棒上環
A washer on a vertical steel rod may start spinning instead of simply sliding down. Study the motion of the washer and investigate what determines the terminal velocity.
A metal disk with a hole at its centre sinks in a container filled with water. When a vertical water jet hits the centre of the disc, it may float on the water surface. Explain this phenomenon and investigate the relevant parameters.
A simple electric oscillator can be made using a bimetallic contact-breaker. Investigate the relevant parameters that affect the frequency of such an oscillator.
一個簡單的電子振蕩器可以用雙金屬接觸斷路器來制作。研究影響這種振蕩器頻率的相關參數。
6. Tennis Ball Tower 網球塔
Build a tower by stacking tennis balls using three balls per layer and a single ball on top. Investigate the structural limits and the stability of such a tower. How does the situation change when more than three balls per each layer and a suitable number of balls on the top layer are used?
To land a coin on its side is often associated with the idea of a rare occurrence. What should be the physical and geometrical characteristics of a cylindrical dice so that it has the same probability to land on its side and one of its faces?
Place two electrodes into water, supply a safe voltage and use a voltmeter to determine electric potential at various locations. Investigate how the measured equipotential lines deviate from your expectations for different conditions and liquids.
If a stream of liquid is launched through a small hole, then under certain conditions it twists into a spiral. Explain this phenomenon and investigate the conditions under which the spiral will twist.
When a drop of a water mixture (e.g. water-alcohol) is deposited on the surface of a hydrophobic liquid (e.g. vegetable oil), the resulting drop may sometimes fragment into smaller droplets. Investigate the parameters that affect the fragmentation and the size of the final droplets.
Connect two metal balls with an elastic band, then twist the elastic band and put the balls on a table. The balls will begin to spin in one direction, then in the other. Explain this phenomenon and investigate how the behaviour of such a "pendulum" depends on the relevant parameters.
Sprinkle small floating particles on the surface of water in a bowl. Bring a strong magnet above and near to the water surface. Explain any observed motion of the particles.
在碗中的水面上撒上漂浮的小顆粒。在水面上方和附近放一塊強力磁鐵。解釋所觀察到的粒子運動的所有模式。
13. Candle Powered Turbine 蠟燭動力渦旋機
A paper spiral suspended above a candle starts to rotate. Optimise the setup for maximum torque.
懸掛在燃燒蠟燭上方的紙螺旋將會發生旋轉,優化設置以獲得最大扭矩。
14. Ball on Membrane 膜上球
When dropping a metal ball on a rubber membrane stretched over a plastic cup, a sound can be heard. Explain the origin of this sound and explore how its characteristics depend on relevant parameters.
If particles are suspended in a liquid that has a lower density than the particles, the particles will settle to the bottom of the container. The rate of settling can be affected by tilting the container that holds the liquid. Explain this phenomenon and investigate the effect of relevant parameters.
When rotating a rod coated with a viscous liquid (e.g. honey), under certain conditions the liquid will stop draining. Investigate this phenomenon.
當旋轉一根涂有粘性液體(如蜂蜜)的棒時,在一定條件下,液體會停止流下,研究這一現象。
17. Invisibility 隱形
Lenticular lenses can be used to distort light and make objects disappear. Investigate how changing the properties of the lens and the geometry of the object affect the extent to which the object can be detected.