任務Task
設計和製作一件散熱背心，供需要在酷熱的環境下工作的人使用。
Design and make a cooling vest for workers who need to work in very hot conditions.
背景知識Background knowledge
首先，讓我們重温熱傳遞的過程﹕
透過傳導，熱可從物體較熱的一端傳遞至較冷的一端。一般來說，金屬是熱的良好導體，非金屬是熱的不良導體。水和空氣都是熱的不良導體。
First, let’s revise the heat transfer process:
Conduction transfers heat through an object from the hot end to the cold end. In general, metals are good conductors of heat and non-metals are poor conductors of heat. Water and air are poor conductors of heat.
在對流中，熱透過液體（或氣體）的流動從一處傳遞至另一處。容器的水被加熱時，熱水會向上流動。它們原本的位置會被周圍較冷的水填補，形成對流。
Convection transfers heat in a liquid (or a gas) by the movement of the liquid (or the gas). When the water at the bottom of a container is heated, the hot water rises to the top. Its place is taken up by the surrounding cold water and this produces a convection current.
熱可透過輻射在真空中傳遞。黑色暗啞的表面既是良好的輻射吸收體，亦是良好的輻射發射體。淺色光亮的表面既是不良的輻射吸收體，亦是不良的輻射發射體。
Heat can be transferred through a vacuum by radiation. Dull black surfaces are good absorbers of radiation and good emitters of radiation. Shiny silver surfaces are poor absorbers of radiation and poor emitters of radiation.
第一部分—設計和製作散熱背心Part A—Design and make a cooling vest
老師會把全班分成數組。試和你的組員合作設計和製作散熱背心。
Your teacher will divide the class into groups. Collaborate with your group members to design and make a cooling vest.
1.
在互聯網搜尋製作散熱背心的不同方法。列出你的設計所需的物料。
Search the Internet for different methods of making a cooling vest. List the materials your group will choose to make the cooling vest.
2.
在以下的空位內繪畫你的設計，並在各部分加上標註。試簡單描述製作散熱背心的步驟。
Draw your design below. Label all the parts. Also, briefly describe how you will make the vest.
3.
寫出你的設計的參考來源。
Write the source(s) of reference that your model is based on.
4.
得到老師的許可後，你現在可以和組員收集所需物料和製作散熱背心。
After getting your teacher’s approval, you can collect your own materials and make the cooling vest.
第二部分—使用littleBits設計和製作一頂「散熱帽」Part B—Design and make a ‘cooling hat’ using littleBits
If littleBits are available at school, you can also make a ‘cooling hat’ using littleBits. Let’s look at the following reference:
e-aristo.hk/r/isstemu5i02web1.e
第三部分—評價和改良Part C—Evaluate and redesign
3.
你認為哪一組的設計是最好的？寫出他們的設計的兩個優點。
1.
Your teacher will evaluate your cooling vest using the following Grading Rubric:
2.
Present and display your cooling vest in class.
3.
Which group’s design do you think is the best? Give two advantages of their design.
4.
What modifications can you make to your cooling vest?
5.
Submit Student’s Worksheets to your teacher after the lesson.