• 生活中有趣的物理 演示實驗


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    • Abstract: 走進清華科學殿堂. 快樂玩物理、探究竟. 演示教學目錄. 一、力學篇. 二、波動篇. 三、熱力篇. 四、電學篇. 五、磁學篇. 六、光學篇. 七、能源篇. 一、力學篇. 氣墊船 (Hovercraft) ... (1D Kinesthetics Cart)體驗運動. 二維動力台車 (2D Kinesthetics Cart)體驗運動. 雲霄飛車 (Complete Roller Coaster) ...

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生活中有趣的物理
演示實驗
走進清華科學殿堂
快樂玩物理、探究竟
清華大學物理系
普通物理實驗室
演示教學目錄
一、力學篇
二、波動篇
三、熱力篇
四、電學篇
五、磁學篇
六、光學篇
七、能源篇
一、力學篇
氣墊船(Hovercraft)力學體驗運動(兩套)
一維動力台車(1D Kinesthetics Cart)體驗運動
二維動力台車(2D Kinesthetics Cart)體驗運動
雲霄飛車 (Complete Roller Coaster)實驗-圓周運動、離心

離心軌道-重力位能和旋轉動能之能量轉換
麥斯威爾飛輪(Maxwell Wheel)-能量轉換
雙珠競走--走捷徑比較快?
投射撞擊百發百中實驗-自由落體&拋體運動
由低處滾往高處滾動的雙錐體-重心問題
角動量守恆的親身體驗-飛輪與旋轉椅的相對旋轉運動
空氣砲彈(Air Cannon)-氣渦流力
鐵鍊栓環喜結良緣(Make a good match)
二、熱力學篇
伽利略溫度計(Galileo Thermometer)
不停地喝水的鳥(Thermodynamic driking bird)
熱動力沸騰器(Thermodynamic Boiler)-液氣相轉變示
範實驗
Hand Bubbler Boiler Pen Demonstrates Energy
Transfer
輻射計(Radiameter)-光熱轉輪
咖啡杯上的史特林引擎(Stirling engine)
翅膀揮舞的蝴蝶-是熱縮冷脹嗎?
紫外光偵測珠(Ultraviolet Detecting Beads)
太陽能袋World’s Largest Solar Bag
六、光學篇
Ghostly Optical Illusion-看得到卻捉不著的影像光學
反射鏡組
偏振(極)片(Polarizing Sheets)--光消失了,影像也就
看不見了!
掌上簡易光譜儀-使用光柵片製作簡易的光譜儀
物理學防偽技術
旋轉紙陀螺--將黑白變七彩!
折光潛影-偽鈔辨識、雙影像、動畫、、應用
具放大鏡功能之輕便可撓的塑膠放大片
Morie Patterns
Euler’s disk
七、能源篇
太陽能發電
風力發電
太陽能與風力混合發電
氫燃料電池
火力發電模型
V8引擎模型
一、力學篇
氣墊船(Hovercraft)力學體驗運動(兩套)
一維動力台車(1D Kinesthetics Cart)體驗運動
二維動力台車(2D Kinesthetics Cart)體驗運動
雲霄飛車 (Complete Roller Coaster)實驗-圓周運動、離心

離心軌道-重力位能和旋轉動能之能量轉換
麥斯威爾飛輪(Maxwell Wheel)-能量轉換
雙珠競走--走捷徑比較快?
投射撞擊百發百中實驗-自由落體&拋體運動
由低處滾往高處滾動的雙錐體-重心問題
角動量守恆的親身體驗-飛輪與旋轉椅的相對旋轉運動
空氣砲彈(Air Cannon)-氣渦流力
鐵鍊栓環喜結良緣(Make a good match)
氣墊魔毯(Hovercraft)力學體驗運動
The Hovercraft is designed to help students experience frictionless
motion, thus better understand Newton's Laws.
Its large platform provides enough area for the rider to comfortably
sit while riding.
The durable Nylon skirt will withstand the rigors of the classroom
environment.
The optional Cordless Air Source is a convenient way supply air to
the Hovercraft, however most vacuums/blowers used in a wood shop
will also be sufficient to lift the Hovercraft.
Movie file
Manual
一維動力台車
(1D Kinesthetics Cart)
體驗實驗
Key Features -PASCO SE8747
The Student "Becomes" the Dynamics Cart
Experience the Feel of Physics Concepts
When a student sits on top of the Kinesthetics Cart, he or she actually
becomes part of the experiment.
Active involvement makes for "fun physics," but, more importantly, it
provides a sensory experience, or "kinesthesia," that teaches what a
concept such as Newton's First Law "feels like."
Students' common misconceptions are quickly eradicated.
The experience is retained in "muscle memory" and helps the student
understand and remember the concepts.
一維動力台車
(1D Kinesthetics Cart)
-PASCO SE8747
Features:
1. Ball bearings mounted on the bottom of the upper cart allow it
to slide off the lower cart
2. Low "Roller Blade" Wheels on both carts allow for smooth,
constant travel
3. Coupler keeps carts piggy-backed until rider removes it
4. Cart length of 90.5 cm
Typical Experiments
of 1D Kinesthetics Cart
1. Newton's First Law
2. Newton's First Law
3. Newton's Second Law
4. Newton's Second Law
5. Coin-toss Misconception Demo*
6. Projectile Motion* Experimental Manual
7. Uniform vs. Accelerated Motion*
*These experiments require
8. Newton's Third Law
additional equipment not
9. Center of Mass -- The Boardwalk*
included with the
10. Simple Harmonic Oscillator*
Kinesthetics Cart.
11. Human Oscilloscope*
12. Collisions: Newton's Third Law
13. Newton's Third Law Misconceptions
14. Newton's Third Law Misconceptions
15. Newton's Third Law Misconceptions
Sample: Experiment 1 - Newton's
First Law Demonstration
1. One rides on the piggy-backed carts at initial velocity, Vo. He
removes the coupler as he approaches the block fastened to the floor.
2. The lower cart strikes the block and stops, but the upper cart and
student continue to move forward at velocity, Vo.
3. The slight jolt that the student feels when the wheels hit the floor will
help ingrain Newton's First Law in the student's memory.
4. Newton's First Law: An object in motion continues in motion, unless
acted upon by an external force.
Experiment 6
-Independence of the
X and Y Motion of a Projectile
Experiment 9:
Center of Mass
Conservation of Momentum
Newton’s Third Law- “A Crushing Experience”
Experiment 6a:
Independence of the X and Y
Motion of a Projectile
Experiment 4:
Newton’s Second Law
-“The Bucket Accelerator”
二維動力台車(2D Kinesthetics Cart)
力學體驗運動
With this circular, 6-wheeled cart, students can "feel" the forces and
accelerations that occur during two-dimensional motion such as circular and
trajectory motion. This cart enables students to directly experience
centripetal force, and it allows quantitative verification of the relationship
between centripetal force, orbital period and the radius. As they sit on the
cart, students will finally be convinced that centripetal force is directed
radially inward.
Manual-2D KINESTHETICS CART
The Foucault Pendulum Demonstration
In the rotating frame of the rider, the plane of
the pendulum rotates, although in the lab frame
its plane of oscillation remains fixed.
The Foucault
Pendulum in action.
雲霄飛車實驗
(Complete Roller Coaster)
The Roller Coaster including the track and Mini Cars
and some accessories allows the quantitative study of
energy and motion.
Key Features:
1. 3-Car Roller Coaster
2. Quantitative Studies of
Energy Conservation
3. Easy to Change Track
Configurations
雲霄飛車實驗(Complete Roller Coaster)
Typical Applications:
1. Conservation of Energy-Release the Mini Car and measure its
velocity and height at several points along the track. Use these values
to calculate total energy of the Mini Car. Frictional losses are less than
5%.
2. Constant Acceleration-Several straight inclined sections can be used
to measure and demonstrate constantly accelerated motion.
3. Projectile Motion/Conservation of Energy -- Use the initial height
of the Mini Car to determine its speed as it flies off the end of the
track. Using this speed and height above the ground when it leaves the
track, predict where the Mini Car will land.
將裝有一小重物的塑膠燒杯置放於滑車上,使
滑車從含有圓形軌道的最左側軌道上滑落下,
觀察滑車在整個軌道上的運動情形。
雙珠競走--走捷徑比較快?
目的:展現運動物體的速度與加速度間的關係、向量分解。
實驗:演示示範影片
1. 初始速度相同的兩個球在具相同水平位置的起點和終點,但路
徑不同的軌道上競走。其中一球不受加速度影響,另一球軌道
於鉛直面上高度先下降後再上升。
2. 將兩球放置在發射架上,以磁控開關使兩球的發射條件和初始
的運動速率相同。將球發射,觀察哪一顆球先抵達終點。
思考問題
1. 兩球最終速度是否相同?
2. 較快抵達終點是否意味過程中獲得能量? 這些能量從何而來?
3. 兩球的時間差與什麼條件相關?
4. 下降的球不論多深都回得來?
5. 加入球轉動的情形將會如何?
6. 加入摩擦力考慮,結果如何?
討 論
1. 兩球最終速度是否相同?
2. 比較快抵達終點是否意味過程中獲得能量?
這些能量從何而來?
3. 兩球的時間差與什麼條件相關?
4. 下降的球不論多深都回得來?
5. 加入球轉動的情形將會如何?
6. 加入摩擦力考慮,結果如何?
離心軌道
為何小鋼球不會從軌道的頂端掉下?而改變軌道的
角度,還可以示範其他的拋體運動。本組包含鋁製
圓周軌道、小鋼球及木製底座。
投射撞擊--百發百中實驗
Experiment 1: Projectile Motion
The purpose of this experiment is to predict and verify the range of a
ball launched at an angle.
The initial velocity of the ball is determined by shooting it
horizontally and measuring the range and the height of the Launcher.
1. 使發射器中的小鋼球對準另將
作自由落體運動的物體發射做
拋體運動。
2. 調整發射方向於兩球在一連線
上。
3. 發射小鋼球,觀察兩球相碰撞
之點。
4. 調整拋體的發射仰角和被射物
體的高度,重新觀察兩球相碰
撞的情形。
演示影片:投射撞擊1, 2, 3, 4
由低處滾往高處滾動
的雙錐體
目的:觀察物體的重心與滾動運動間的關係。
實驗:
1. 兩個圓錐底面連結在一起形成一個雙錐體。
2. 一個V字型的軌道,使V字型尖端的部分低於另一端。
3. 將雙錐體橫跨放置於V型軌道上較低的一端,觀察雙錐
體滾動的方向。
示範影片:http://demo.phy.tw/experiment/dynamics/double-cone/
原理思考
1. 雙錐體為何會由低處往高處的方向滾動?
2. 雙錐體的錐角、V型軌道的張角與軌道面的斜度對本物
體的滾動方向有何影響?
Double Cone rolls upward on a plane
Demonstration: Ascending Cone-Defy gravity as our cone appears
to roll upward.
This visual demonstrator of the center of gravity consists of a wooden
frame with diverging rails and a double-ended cone.
The cone appears to roll upward; in actuality, it is the center of mass
that is moving downward.
The physical explanation:
(a) The center of mass of the cone is descending.
(b) The motion may be described by the energy
conservation law for the cone-Earth as follows:
(1/2)mv² + (/2)Iω ² + mgw = constant
I = (3/5)mR² = rotational inertia of double cone
with respect to symmetry axis
Where m = mass (g), R = radius (cm), v = velocity (m/s2) and ω = angular velocity
(rad/s), w = instantaneous height of center of mass of double cone over zero level of
potential energy.
問 題 討 論
1. 比較一般圓柱或輪子在斜面上的滾動與本實驗有何不
同?
2. 雙錐錐角大、軌道開角大、軌道斜角小是向上滾的條
件嗎?
3. 如果沒有摩擦力,結果會如何?
4. 雙錐爬到何處會停止?會再滾回來?
5. 若雙錐中的一錐為空心,一錐為實心,結果如何?
6. 如果雙錐以尖端部分相連結來做實驗,結果如何?
延伸實驗:可以將兩個塑膠漏斗開口部分用膠帶黏住,
以筷子做軌道架,在書本上做本實驗。
角動量守恆的親身體驗
-飛輪與旋轉椅間的相對旋轉運動
目的:體驗角動量變化的效果。
實驗裝置:活動轉椅,飛輪和電鑽。
1. 演示者坐在活動轉椅上,手持飛輪。
2. 另一位同學以手或電鑽讓飛輪快速轉動,演示者變動
飛輪面的方位,觀察演示者座椅的轉動和飛輪轉動間
的相對變化情形。
演示影片一、二
原理思考
1. 當演示者將飛輪軸順時針方向旋轉時,
旋椅轉動方向為何?
2. 當演示者將飛輪軸逆時針方向旋轉時,
旋椅轉動方向為何?
討論
演示者先感受到雙手轉變飛輪軸時傳回來一股扭力,他為了維
持坐姿,雙腿會用力因而帶動座椅旋轉。
關於實驗與
1. 座椅必須非常滑順,摩擦力越小時的效果越佳。
2. 飛輪直徑越大而且重量越重時,效果越好。
實驗注意事項
操作時注意演示者的安全,飛輪脫手或演示者摔倒都容易造成
受傷。演示助教必須要有豐富的操作經驗才能上場。
Maxwell Wheel
Refer ppt file
Useful for demonstrating momentum,
conservation of energy and torque, this
apparatus is basically a large metal
flywheel suspended by two strong cords
in a metal frame.
The cords are wound around the shaft
of the wheel which is then released. The
wheel will unwind as it falls but will
wind itself back up as the momentum
carries it upward in the opposite
direction.
This oscillation process will continue
for several moments before gradually
coming to a stop as the wheel slowly
loses momentum and travels less each
time.
Air Cannon (空氣砲彈) or Airsooka Air Gun
-A great demonstration of the energy that can be stored in waves.
The Air Cannon uses a vortex of air for ammunition.
Its unique shape creates a stable toroidal vortex. Pull
back the flexible membrane, release and the
invisible wave front of air can hit a target 20 feet
away!
Airzooka air gun
Launch a full air assault without ever leaving the ground with
the 'Airzooka air gun'.
Airzooka is a hand held fun gun that fires a ball of air with
enough power to mess up a persons hair, ruffle their shirt or
scatter papers from a distance of 20 feet away.
By pulling back the membrane and releasing - a shock wave of
air is sent hurtling at your target.
Requiring no batteries or electricity, Airzooka works with an
elasticated air launcher.
Pull back and release the launcher like a catapult, firing the ball
of air out of the air gun.
Because it shoots air,
you never run out of ammo!
喜結良緣(鐵鍊栓環,Make a good match)
步驟一:用右手大拇指和食指撐起鐵鍊,中指放於大拇
指與食指正下方緊靠手心。
步驟二:將鐵環套於鐵鍊中間,再往上提至右手中指上
方,將鐵環一端放於中指上(拇指食指下)。
Step 1: Use your thumb and forefinger to support the chain
in the center of the ring. At the same time, your
middle finger is close to your thumb.
Step 2: Let the ring lean against your middle finger loose the
ring, then the ring will be hitched by the chain.
二、熱力學篇
伽利略溫度計(Galileo Thermometer)
不停地喝水的鳥(Thermodynamic driking bird)
熱動力沸騰器(Thermodynamic Boiler)-液氣相轉變示
範實驗
Hand Bubbler Boiler Pen Demonstrates Energy
Transfer
輻射計(Radiameter)-光熱轉輪
咖啡杯上的史特林引擎(Stirling engine)
翅膀揮舞的蝴蝶-是熱縮冷脹嗎?
紫外光偵測珠(Ultraviolet Detecting Beads)
太陽能袋World’s Largest Solar Bag
Galileo Thermometer (伽利略溫度計)
Be invented by Galileo Galilei four centuries ago
To indicate the approximate current temperature.
How does a Galileo thermometer work?
Based on a thermoscope invented by Galileo Galilei in the early
1600s.
A simple, fairly accurate thermometer, today it is mostly used as
decoration.
Be consisted of a sealed glass tube that is filled with water and
several floating bubbles.
The bubbles are glass spheres filled with a colored
liquid mixture. This liquid mixture may contain alcohol,
or it might simply be water with food coloring.
Attached to each bubble is a little metal tag that
indicates a temperature. A number and degree symbol
are engraved in the tag.
These metal tags are actually calibrated counterweights.
The weight of each tag is slightly different from the others.
Since the bubbles are all hand-blown glass, they aren't exactly the same size and
shape. The bubbles are calibrated by adding a certain amount of fluid to them so
that they have the exact same density.
So, after the weighted tags are attached to the bubbles, each differs very slightly in
density (the ratio of mass to volume) from the other bubbles, and the density of all
of them is very close to the density of the surrounding water.
An object immersed in a fluid experiences two major forces: the
downward pull of gravity and the upward push of buoyancy. It is the
downward force of gravity that makes this thermometer work.
The basic idea is that as the temperature of the air outside the
thermometer changes, so does the temperature of the water
surrounding the bubbles.
As the temperature of the water changes, it either expands or contracts,
thereby changing its density. So, at any given density, some of the
bubbles will float and others will sink.
The bubble that sinks the most indicates the approximate current
temperature.
Galileo thermometer
Consider the example: Let's say there are five bubbles in the thermometer:
1. A blue bubble represents 60oF
2. A yellow bubble represents 65oF
3. A green bubble represents 70oF
4. A purple bubble represents 75oF
5. A red bubble represents 80oF
The blue bubble (60oF) is the heaviest (densest) bubble, and
each bubble thereafter is slightly lighter, with the red bubble being
the lightest.
Now, let's say the temperature in the room is 70oF.
Since the surrounding air is 70oF, we know the water inside the thermometer is
also about 70oF. The blue and yellow bubbles (60 and 65oF, respectively) are
calibrated so that they have higher densities than the water at this temperature, so
they sink.
The purple and red bubbles each have a density that is lower than the surrounding
water, so they float at the very top of the thermometer. Since the green bubble is
calibrated to represent 70oF, the same temperature as the water, it sinks slightly so
that it is floating just below the purple and red bubbles -- thereby indicating the
room's temperature!
Solution
A Galileo thermometer combines Archimedes' principle with the fact that liquids generally
expand faster with increasing temperature than solids do.
Each sphere in the thermometer has an average density (a mass divided by volume) that is
very close to that of the fluid in the thermometer.
As stated in Archimedes' principle, if the sphere's average density is less than that of the fluid,
the sphere floats and if the sphere's average density is more than that of the fluid, it sinks.
But the fluid's density changes relatively quickly with temperature, becoming less with each
additional degree.
Thus as the temperature of the thermometer rises, the spheres have more and more trouble
floating.
Each sphere's density is carefully adjusted so that it begins to sink as soon as the
thermometer's temperature exceeds a certain value.
At that value, the expanding fluid's density becomes less than the average density of the
sphere and the sphere no longer floats.
The spheres also expand with increasing temperature, but not as much as the fluid.
Here is a picture of a combined Galileo thermometer and simple barometer.
In addition to measuring the temperature with floating spheres, this device measures the
outside air pressure with a column of dark liquid.
It has a trapped volume of air that pushes the liquid (visible at the bottom of the unit) up a
vertical pipe when the outside air pressure drops.
喝水不停的熱力學鳥
一開始喝水,就喝個不停的鴨子
鴨子喝水是常見的科學玩具,仔細觀察裝置
的結構及操作過程,思考其原理。
實驗:將鴨子的頭部(嘴喙)浸入水中後放手,
鴨子回到平衡位置附近搖搖晃晃。不久後,
又開始自動將頭部浸入水中,繼續喝水。鴨
子一旦開始喝水,就會重複喝水的動作。如
此過程可以不斷重複。
一個熱能與機械能互相轉換的熱力學過程。
The dunking is due to the evaporating water, which cools the head
reducing the pressure of the gas inside. The liquid inside the bird rises
up from his tail towards his head, causing the bird to tip and appear to
be drinking. As the bird dunks, the liquid returns to its tail, and the
process begins again.
原理探討
鴨子喝水其實是個熱力學過程,是將熱能轉為機械能的過程。為什麼可以這麼
說?我們先作以下的觀察和思考:
1. 鴨子的頭和身體分別是玻璃球,透過一根玻璃管連接。
2. 將頭部浸入水中時,內部液體怎麼流動?
3. 頭部濕了以後,溫度會下降還是上升?會怎麼影響氣體的壓力?
4. 頭部浸水後放手,是什麼讓鴨子回到直立的狀態(進而搖晃)?鴨子的重心在哪
裡?會因為液體的流動而改變嗎?
5. 搖搖晃晃的過程有什麼作用?
6. 鴨子的頭部(嘴喙)是什麼材質?會影響結果嗎?
7. 內部液體是特殊的嗎?有什麼性質?水可以嗎?
8. ”(二氯甲烷), “ether”(乙醚)等。
進一步問題探討
1. 環境的濕度會影響鴨子重複喝水的頻率嗎?
2. 水杯裡的水溫會影響鴨子重複喝水的頻率嗎?水冷些或熱些的影響是什麼?
3. 鴨子可以重複喝水的動作,能量是哪裡來的?有沒有違背能量守恆定律?一般
的單擺在擺動一段時間後也終會因為摩擦力而停止,為什麼鴨子不會?我們的
確看到當鴨子搖晃的程度漸漸變小後,不一會兒怎麼又「自動」將頭伸入水中
。這「神奇」的能量是哪裡來的?
Thermodynamic Drinking Bird
The ‘Drinking Bird’ is disguised as a great demonstration of
thermodynamics.
When the head of the bird is moistened with water it will repeatedly tip over
and appear to be drinking from a cup placed in front of it.
The dunking is due to the evaporating water,
which cools the head reducing the pressure of
the gas inside. The liquid inside the bird rises up
from his tail towards his head, causing the bird
to tip and appear to be drinking. As the bird
dunks, the liquid returns to its tail, and the
process begins again.
In essence this is a small, cleverly designed
thermodynamic engine which only needs water
to run!
Avoid breaking glass, contains methylene
chloride (二氯甲烷) and may stain clothing and
other surfaces.
Do not swallow or allow to come into contact
with eyes. Flammable. Keep away from flame
and other heat sources. CHOKING HAZARD:
Setup: Wet cloth which covers the tube in the bird (i.e. wet bird's
head) and set up the bird with a beaker in front of it. The gas in the
birds, which consists of various organic fluids, will condense
causing the birds to "drink". The water cools and reverses the
condensation process and the bird settles back down.
Concepts Displayed: condensation, expansion, Rankine cycle
Click Here to see a short videoclip of the demonstration.
Click here for a more detailed explanation of how it works
http://noether.physics.ubc.ca/xcart/product.php?productid=16665
Thermodynamic Boiler
-液氣相轉變示範實驗
This thermodynamic hand boiler is made of hand-
blown glass.
The liquid inside these beautiful boilers shoots up
the tubes and appears to boil when you hold it in
your hand.
封閉的玻璃容器內,裝有酒精等易揮發的液體。
http://tw.9s2u.com/
在下端以手掌握住後,由於溫度升高,液體轉變
成氣體。
在固定容積內,溫度上升,氣壓增加,便將下部
的液體推擠至上部的球中。
手一拿開,溫度回降至室溫,氣壓隨之降低,上
球的液體又流回下球中。
簡單有趣的小道具,可以清楚地解釋液氣相的變
化、空氣壓力等物理現象。
Hand Bubbler Boiler Pen
Demonstrates Energy Transfer
Hold the bottom chamber between your fingers and
watch as your body heat warms the liquid.
As it starts to vaporize, it expands moving it's way
through the tubes to the upper chamber. When all the
liquid has reached the top, a bubbling effect is
created!
Let go and the liquids cool, and move back down to
the lower chamber. Great for science class! Includes
matching stand.
WARNING: Not intended as a toy for children.
1. Contains Ethyl Alcohol. Avoid contact with eyes. In
case of eye contact, flush thoroughly with water. If
irrigation persists, get medical attention.
2. Do not use near heat or flames. Only warn using
your hand. Liquid will stain if glass is broken.
3. Keep out of reach of children.
輻射計(Radiameter)
-光熱轉輪
現象:黑白葉片照光會轉,
是光壓作用?還是電磁作用?
能否反向轉?
可否以其他方式也使之旋轉?
目的:觀察黑白葉片旋轉的機制
實驗:
1. 封閉玻璃容器的中間支撐一可自由旋轉的轉輪,轉輪由四片葉片
組成,葉片的兩面分別為黑色與白色。
2. 當使用光源(傳統檯燈,太陽光,手電筒皆可)照射到葉片上,便
會逐漸開始轉動。移開光源,葉片即停止轉動。
3. 改以雷射筆或LED燈泡的手電筒照射葉片時,轉輪不會轉動。
4. 用手電筒照射葉片白色那面時,轉輪不會轉。但照到黑色那面時
,轉輪就迅速轉動起來。
5. 分別(1)改用吹風機以加熱方式或(2)以熱乎乎的毛巾及(3)冰冷的
毛巾包覆玻璃器的上端,再仔細觀察黑白葉片轉動的情形。
輻射計(Radiameter)深層思考
此裝置很容易由網路購得的科學小玩具,價錢僅約US$10左右,台
灣賣~NT$650-800。提供給滿八歲以上的孩童於把玩過程,透過觀察
有趣的物理現象,學習並探究其原理。但其中所蘊含的物理原理卻
值得深思。
問題:為何葉片會旋轉?如何決定葉片旋轉的方向?
如果是光壓?光子打到白色葉片時,動量變化應是打到黑色葉片的
兩倍(想一想為什麼?),所以不論照黑色面或白色面,轉輪應該都會
轉,而且照白色那面時,應該轉動更快才是。可是這跟觀察三不符

1. 是電磁作用嗎?仔細觀察轉輪的結構,組成的都是元件都是絕緣體
,如果是與電磁現象相關,會有產生電流或磁場等裝置,似乎沒有
看到?
2. 如果照光就會轉,那為什麼照射雷射光時,應該卻一點兒動靜也沒
有?(觀察二)
3. 難道是光電效應?那使用雷射或LED手電筒不是更好嗎?
4. 照黑色與白色有差別?因為黑色容易吸熱,所以造成旋轉的機制與
熱有關嗎?
5. 為何以吹風機或冷熱毛巾的熱能也能啟動葉片的旋轉?
進一步更深度的探討
1.玻璃容器內部是一大氣壓?還是真空?抑或是某特殊壓力?
2.內部是否有氣體?有的話,是哪一種氣體?
3.玻璃容器內部需要填充特別的氣體嗎?
4.不小心打破玻璃容器後,直接照光於轉輪上還會有同樣的結
果嗎?
5.如果葉片不是一面黑一面白,若兩片全黑或全白,葉片照光
還會旋轉嗎?
6.若一黑一白的葉片改塗成其他不同的顏色,您認為現象會如
何改變?
7.可辦小型競賽,如比賽方式可比賽組裝使特林引擎的技巧,
或利用光電閘紀錄飛輪轉動的圈數及總轉動時間,最多圈及
時間最長者勝出。競賽可大幅提高學習者的實驗動機及趣味
性。
咖啡杯上的史特林引擎
(Stirling engine)
透視引擎的視覺化運作!
目的:藉由透視史特林引擎的運作
,瞭解抽象的熱力學循環過程。
實驗:組裝好的史特林引擎置於裝滿熱水的杯子
上。熱水的熱能透過引擎氣室下方的金屬板傳導
至氣室內金屬板和白色活塞之間的氣體。此時稍
微撥動一下飛輪,引擎即開始轉動。當氣室上下
兩金屬板的溫度差越大,飛輪則旋轉地越快。引
擎就靠著熱水所提供的熱能量,持續轉動,直至
水溫冷卻到接近室溫,引擎才逐漸停止旋轉。
工作機制:熱能 動能的能量轉換機制,即蒸汽引擎的工作原理
應用:(1)早期推動蒸汽火車和蒸汽汽車前進的主要機制。
(2)火力發電廠中帶動發電機高速旋轉發電的主要機制發電廠中的
能量轉換流程:化學能 熱能 動能 電動。
史特林引擎
-推動科技進步、改善人類生活品質
的關鍵性發明
史特林引擎,又稱發動機:是一種活塞式熱氣
引擎
經由外部加熱裝有氫氣或氦氣氣體的密封氣室
,使氣體受熱膨脹,進而推動活塞做功。
膨脹後的氣體在冷氣室冷卻,然後進入下一個
流程。同樣只要有一定值的溫度差存在,都可
以形成斯特林發動機,比如上面這個咖啡杯上
的斯特林發動機,如果下面是冰塊,它也能轉
起來,而且比裏面是熱咖啡(或熱水)還要持
久,一個小時左右。斯特林發動機可以使用多
種的燃料,各種可燃氣體估計是最佳材料,
Dean Kamen還用牛糞來作過燃料。而且排氣潔
淨,還有一個優勢相對於內燃機來說,因為沒
有氣體爆炸,所以大大降低了噪音污染。
原理思考
史特林引擎中的熱力學循環過程
「卡諾循環」(Carnot-cycle engine)
左圖是引擎內工作氣體的工作圖 PV相圖
• 縱軸是工作氣體的壓力
• 橫軸是工作氣體的體積
• γ 為工作氣體的體積壓縮比。
理想的史特林引擎是由兩個等溫過程及兩個等體積過程組成的
熱力學循環。
等溫壓縮(a b):工作氣體的溫度T1 不變,但壓力上升。
等體積加熱(b c):從熱水的熱蒸汽中獲得熱能。
等溫膨脹(c d):工作氣體的溫度不變 T2 ,但壓力減小。
等體積冷卻(d a):將熱能排至環境。
理想狀況下,若T1 與T2固定的情況下,史特林引擎的效率等於
理想「卡諾循環」的熱機效率
深入探討
使特林引擎的循環對應的熱力學過程為何?
氣體在不同的階段和過程中,氣體的壓力、體
積及溫度的關係為何?
飛輪的旋轉方向與引擎的機構設計有關嗎?還
是由初始旋轉方向決定?
如果熱水的溫度增加,會影響什麼?
可用什麼方法讓引擎運轉的時間持續增加?
日常生活中充滿了使特林引擎運用的物品,您
知道有哪些嗎?
問題:是熱縮冷脹嗎?
現象:通電,蝴蝶的翅膀會揮舞
老師的答案:這可不是熱漲冷縮哦!
目的:介紹反直覺的物理現象。
實驗:在一迴路中加入特殊金屬絲並通入電流,觀察通
電前後特殊金屬絲的變化。
思考:一通電,物體就會被往上拉了?上頭是有裝馬達
嗎?要不然怎麼一通電就往上拉。,通電的目的
是為了加熱該金屬絲,使其改變形狀,以達到此
實驗所想表現的現象。
討論:請舉出非熱漲冷縮的例子。
備註:本實驗利用通電的方式加熱,取代用火所造成的
不均勻加熱。
參考資料:Wikipedia-Shape memory alloy
形狀記憶合金
(Shaped memory Alloy, SMA)
簡稱記憶合金,又稱智慧型合金。
是一種對溫度特別敏感的特殊材料,當環境溫度變化時,由於材
料的內應力作用,使得材料發生變形,而當環境溫度恢復後,該
材料也隨即恢復為原來的形狀,這就是所謂的記憶合金。
包括鎳鈦合金、銅鋅合金、銅鋁鎳合金以及銅金鋅合金等,現在
也已有以鐵合金及不銹鋼合金製成的記憶合金材質。
除了形狀記憶合金之外,近些年來還出現了形狀記憶塑膠,某些
高分子聚合物也具有形狀記憶的功能。例如,日本有一種形狀記
憶塑膠,它是苯乙烯和丁二烯的聚合物,這種聚合物加熱至60oC
時,丁二烯開始軟化,而苯乙烯仍然保持堅硬,如此就能展現其
形狀記憶的性能。
形狀記憶合金和形狀記憶塑膠的開發,對於玩具業的發展有很好
的推動作用。應用十分廣泛,在日本利用記憶合金推出了不少新
穎別致的商品,可用於玩具、電子產品等領域。
NIMS已開發出形狀記憶合金薄膜驅動器的簡易
製造技術-引自 2007/07/09【日經BP社報導】
- http://big5.nikkeibp.co.jp/china/news/news/200707/mech200707090130.htmlㄝ
記憶合金應用十分廣泛:
如機械上的固緊銷、管接頭,電子儀器設備上
的火災報警器、插接件、積體電路的釺焊。
醫療上的人造心瓣膜、脊椎矯正棍、頭顱骨修
補整形、口腔牙齒矯形和頜骨修補手術等。
在通訊衛星、彩色電視機、溫度控制器以及玩
具等方面發揮神奇的效能,也將成為現代航海
、航空、航太、交通運輸、輕紡等各條戰線上
的新型材料。
已上市的記憶合金產品
鈦鎳形狀記憶合金下尿路擴展支架
記憶合金食道支架
記憶合金作為防偽材料的應用
醫用高強度記憶合金矯形棒
一種記憶合金薄壁管內支架
網格狀記憶合金超彈性文胸托杯
記憶合金食道支架
記憶合金人體椎體
記憶合金防偽標誌
單側骨皮質記憶合金釘
一種記憶合金易拆卸環抱式加壓接骨器
記憶合金無聲脈動電機
記憶合金脊柱棒
形狀記憶合金溫控器
滅火器用記憶合金彈簧收縮式感溫驅動裝置
Ultraviolet Detecting Beads - UV Science and Fun
These UV beads are an inexpensive fun way to make the invisible become visible.
The solar pony beads are pale in visible light, such as indoors or if they are shielded by a
UV screen such as automobile glass or sunglasses. The Ultra-violet sensitive beads contain
a pigment which changes color when exposed to UV light from the Sun or other UV source.
Many of today's space telescopes observe colors of light not in the visible spectrum such as
infrared and ultraviolet.
One can make a simple bracelet from a standard pipe cleaner or strip of rawhide which can
function as a UV detector. Use your imagination to think of other things to use them for.
Many other experiments are possible as well... test sunglasses for the effectiveness of their
UV protection, or even suntan lotion.
In five assorted colors, all beads are pale, off-white in the absence of UV light.
The ultraviolet beads will cycle back and forth (to bright colors and back again) over
50,000 times!
Become an ultraviolet detective with these amazing UV-sensitive beads! It's solar magic in
action!
Make bracelets, test the effectiveness of sunscreen, or experiment with color while you
learn about the power of sunlight. Included is a science activity guide with lots of fun
experiments with solar radiation and light.
紫外光激發變色材料與防偽油墨
在太陽光下,能發出可見光(400~800nm)的材料和防偽印刷油墨

這類材料和油墨從表面上看是由於太陽作用而變色,實質上也是
受紫外線照射而變色的。
目前市場上已開發應用的此類材料在太陽光(也可在紫外光)下,
即發生變色效果,可以從無色變紫、藍、黃等色,也可設計為從
有色到無色變化。
是防偽材料中的新秀、奇葩。
Ultraviolet Detecting Beads - UV Science and Fun
Become an ultraviolet detective with these amazing UV-sensitive
beads! It's solar magic in action! Make bracelets, test the
effectiveness of sunscreen, or experiment with color while you learn
about the power of sunlight. Included is a science activity guide with
lots of fun experiments with solar radiation and light.
Ultraviolet Beads glow with bright colors when exposed to the sun
or other UV light source, but remain off-white when indoors or not
in the presence of UV.
Students can use UV Beads to design and conduct experiments that
test the effectiveness of UV protection: sunglasses, sun-block, and
automobile glass for example.
Combine science and art to create jewelry and other fun art projects
using the beads. String the colorful little UV indicators together to
create necklaces or bracelets that double as UV detectors. " "
World’s Largest Solar Bag
This amazing item demonstrate principles of density and
buoyancy, as well as solar energy and laws of gases.
The largest on the market today, this solar bag is 50 feet long
and 3 feet in diameter and can be cut in half to make two bags
the same size or two different sizes.
The thin, black plastic bag holds over 350 cubic feet of air.
Experiments (實驗步驟):
Fill the bag by running,
then tie up the ends and
let the solar energy of the
sun heat the air inside the
bag.
Tether the bag with string
and watch it rise into the
sky in only five minutes.
四、電學篇 + 五、磁學篇
韋氏起電機(Wimshurst's Electrostatic Generators)
范式(范德格拉夫)起電機(van de Graaf Generator)
靜電展示與應用
比比哪個磁力比較強?
Spinning Magnet, Levitating Vortex 物體騰空懸浮歷
久不墜
Levitron-Floating Gyroscope
韋氏起電機
Wimshurst's Electrostatic
Generators
構造:由一套安裝在基架
上的透明塑膠盤(上有金屬
片)和萊頓瓶(Leyden jarr就
是電容器)組成
起電機的起電原理
利用感應起電,當兩個起電盤快速旋轉時,會使玻璃
板的一半帶正電一半帶負電,間接使得裝有絕緣手柄
的放電球頂部,分別聚集大量不同電性的電荷,不需
接觸,即可大量放電。
起電機使用的注意事項
1. 搖轉起電機時,必須順時針方向搖,如果逆轉
將不能起電。
2. 搖轉起電機時,速度要由慢至快,轉速不可太
高,否則會影響電刷和箔片的接觸,反而不能
起電。
3. 轉動圓盤後,須注意放電球的極性,略微分開
兩個放電球,慢慢轉動手柄,則帶負電的放電
球上出現微弱的紫色光,帶正電的放電球上出
現分叉的小火花。
4. 調節放電球的距離時,只能操作絕緣柄。如果
停止起電實驗時,


Use: 0.0288