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RISING WATER
*Pranav Khanna and *Juanina Oppel
*Student of AHS Theodor-‐Kramer And
Teacher at AHS Theodor-‐Kramer, Vienna
18.01.13
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Index:Table of Contents: Index……………………………………………………………………………….....Page 1 Plagiarism Pledge………………………………………………………………..Page 2 Abstract………………………………………………………………………………Page 3 Zusammenfassung…………………………………………………………...….Page 4 Introduction…………………………………………………………………….….Page 5-6 Topic.....……………….....................................................................................Page 7 (Hypothesis/goal/question) Method/Materials………………………………………………………….…….Page 8 Results (+Analysis)……………………………………………………...……....Page 9 Dependent Variables/wrong results/ future possibilities………Page 10 Acknowledgement…………………………………………………………….....Page 11 Discussion………………………………………………………………………..….Page 12 References…………………………………………………………………...……...Page 13-14
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I PRANAV KHANNA PROMISE NOT TO COPY AND PASTE TEXT FROM THE INTERNET TO PLACE ON MY PROJECT FILE. IF I DO COPY PICTURES OR A TEXT, WHICH I FIND INTERESTING, THEN I WILL PROVIDE THE LINK OF THE PAGE IN MY REFERENCES.
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Abstract
“Rising water” is an experiment, which shows, how to become a little physicist using everyday objects. After taking a soup plate and pouring water into it, a candle is placed vertically in the middle of the plate. Then light the candle and cover it with a glass, the water will raise. Finally, the experiment is resumed by changing the size of the candle, the temperature of the water and the size of the glass. By using cold water, the water rises about 4,28cm in the glass while the warm water only rises about 3,49cm, averagely (in my experiment). This shows how meaningful the interaction of different factors can result.
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Zusammenfassung "Rising water" ist ein Experiment welches zeigt, wie mit Alltagsgegenständen, jeder ein Physiker werden kann. Ein Suppenteller wird mit Wasser gefüllt und eine Kerze senkrecht in der Mitte des Tellers platziert. Die Kerze wird, dann angezündet und mit einem Glas überdeckt, das Wasser wird steigen. Schließlich wird der Versuch wiederholt, aber die Größe der Kerze, des Glas’ und die Temperatur des Wassers geändert. Wird kaltes Wasser verwendet, steigt dies auf durchschnittlich etwa 4,28 cm im Glas, während das warme Wasser nur ca. 3,49 cm steigt (gilt nur für mein Experiment). Dies zeigt, wie bedeutsam das Zusammenspiel von verschiedenen Faktoren sein kann.
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Introduction:
Many people think that experiments in physics are complicated and need physicists to perform them. In an Austrian newspaper article in 2010, a study proofed that 60 out of 100 people connect with high-‐speed cameras, electron accelerators, etc., when thinking of a physics experiment. But simple tests in everyday life can also be connected with this subject. The experiment “Rising water” shows this very well. A candle is placed in a middle of a plate (which is filled with water) and covered with a glass. The water from the plate will rise.
Now why does this happen? 1”The physical aspect: the candle heats the air and expands it. This cancels the depletion of the oxygen temporarily and the water level stays down. When the oxygen is depleted, the candle goes out and the air cools. The volume of the air decreases and the water rises. The temporary temperature change delays the rise of the water. As several readers have pointed out, also the water condensation should be mentioned. While water is initially gas, it condenses and helps to delay the effect.” The chemical aspect: oxygen O2 and paraffin Cn H2n+2 react. The burning produces water H 2O and carbon dioxide C O 2. For n=1 we balance the equation as follows: 2 O2 + C H 4 = C O 2 + 2 H 2 O Because twice as much oxygen is burned than carbon dioxide released, the air volume decreases. Summary: There are two different effects. Both a chemical and a physical reasoning are needed to explain what we can see. Both physics and chemistry matter. The initial cancellation effect can confuse the observer. Mathematics plays a role when the chemical equations are balanced.” 1Oliver Knill, 2006 Last access to this website: 15.01.2013
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It has been found out, that many people are confident to know that this is basically the reaction, which takes place in the glass. Like this examples show again:
• 2“As you lower the glass over the candle, the flame heats the air inside the glass.
• The glass contacts the surface of the water, trapping a volume of warm air. • The candle goes out and this warm air cools rapidly. • Air that cools rapidly under a constant pressure does so according to
Charles's law[1], a specific version of the ideal gas law that holds the quantity of gas and the pressure constant. Charles's law holds that the ratio of Volume to Temperature is constant.
• Since the temperature decreases, the volume must also decrease. • Additionally, some water vapor may condense on the sides of the glass and
back into the liquid water. This also reduces the total volume of gas inside the glass.
• Fire heats the air in the glass, so the air volume increases causing positive pressure inside. As fire goes out, and the air cools inside the glass, the volume decreases lowering the pressure (forming a vacuum). Then the outside air pressure the with pushes the water into the glass until the pressure inside and outside the glass are equal.”
3“When the burning candle is covered with the beaker, the flame eventually goes out because it uses up all the oxygen. Fire needs oxygen to burn. The other gas left behind has less pressure compared to air. Remember that when the candle burns the oxygen turns to carbon dioxide. Carbon dioxide has less pressure than Oxygen. As a result of the different pressure inside the beaker, the air pressure outside the beaker tries to equalize the lower pressure difference inside the beaker, but does so by pushing the water into the beaker. This is why the water rises. It is sitting between the air outside of the beaker and the left over gases inside the beaker. This isn't the main factor for the rise in the water level though. You will observe that when you place the beaker over the burning candle and on the water, bubbles form in water just outside the rim of the beaker. This is because as the candle becomes closed off in the beaker it increases the temperature of the air in the beaker. Because air and most other gases expand (spread out) when they are heated they take up more volume (space). Therefore the bubbles in the water are air trying to escape the beaker to find more "space." When the flame goes out the leftover air and gases in the jar cool down and they want to contract (move closer together). As this happens, the air and other gases pull the water in and upwards while they "move closer together” or you can look at it as the water is being pushed into the beaker by the outside air pressure.“ These examples show, how easy and fun physics experiments can be as well as how we can use it in every day life.
2 Edited by Dvortygirl, Krystle, Sondra C, Jonathan E. and 23 others, year: unknown 3 Robert Krampf and Steve Spangle, 2007 Last access: 15.01.2013
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THE TOPIC
(EXPERIMENT): Rising water: Take a soup plate and pour water into it. Then get a candle and place it vertically in the middle of the plate. After that, light the candle and cover it with a glass. The further phenomenon is to be explained. Questions: What happens if the candle is covered with the glass and why? Do following the factors have an influence on the experiment:
• Size of the glass? • Size of the candle? • Temperature of the water?
Hypothesis: As I have started the experiment AFTER reading the articles in the Internet, I expect the water to rise in the glass after the candle extinguishes due the difference in pressure caused by some factors. GOAL: The aim of this experiment was, to make it as fair as possible. The method was changed many times as the length of the candle, the amount of water and its temperature have big influences on the results. In addition, the goal was to experiment in a way in which the phenomena of the rising water can be explained without the need to look it up in the Internet. This objective can be reached by taking these factors in consideration:
• Doing as many experiments as needed to come to a conclusion • Trying to get help from Mrs. Oppel and asking questions to a Professor in
the University of Vienna
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METHOD and MATERIALS Materials:
• Three glasses with different sizes (small, medium and big) • Three candles per size (small, medium and big) • One plate in which I can pour 200ml water • One lighter (=fire) • Warm/Cold water
Length of candles: Volume of the glasses: C1 (Candle one): 7,2 cm G1 (small glass): V= 288,31cm3 C2 (Candle two): 10,0 cm G2 (medium glass): V= 591,867cm3
C3 (Candle three): 13,9cm G3 (jar): V=1110,56 cm3
Water used: 200ml per experiment Method:
• To start the experiment, nine candles are required (three per size: small, medium and big)
• Take exactly 200ml of cold water and pour it into a soup plate • Place a small sized candle (see C1) vertically in the middle of the plate • After that, light the candle and cover it with a small sized glass (see G1) • Measure the level of water, that rose in the glass using a ruler • To make the experiment is absolutely fair, the amount of water, which is
still in the plate, is to be measured in order to readjust (if it is less than 200ml, water is poured into the plate again)
• This whole process is then repeated by changing the size of the glass, the size of the candle and doing this whole experiment again, but using warm water.
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The method leads to the following RESULTS:
*C1+G1= *3,6cm (see below) 2,2cm C1+G2= 3,7cm 3,2cm C1+G3 = 4,8cm 4,1cm C2+G1= Water didn’t rise Water didn’t rise C2+G2= 2,8cm 2,3cm C2+G3= 4,0cm 2,7cm C3+G1= *X (see below) X C3+G2= 3,4cm 2,8cm C3+G3= 3,3cm 2,7cm C1+C3+G3= 5,9cm 5,4cm C1+C3+G2= 5,4cm 4,8cm C1+C3+G1= 4,0cm 3,5cm C1+C2+G3= 6,4cm 6,1cm C1+C2+G2= 6,1cm 5,6cm C1+C2+G1= 4,4cm 4,0cm * Candle1+Glass1= cold water rose 3,6 cm in the glass *X= candle was too big for the glass
(Results from C1+G1 to C1+G3) These bars show clearly that cold water rises greater than warm water. Analysis of the RESULTS: Having done all the experiments, it is sure say that this process takes place in the glass: The heat of the flame raises the temperature of the gases trapped in the glass, causing them to push outward against the liquid. When the candle burns out, the temperature will decrease quickly which slows the movement of the molecules that make up the air inside the glass. This creates a lower air pressure inside the glass than outside, the water will rise due to the differential.
0 1 2 3 4 5 6
1 2 3
Cold water: Warm water:
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Dependent Variables: The temperatures of the water, the amount of candles inside the glass and the size of the glass itself, obviously have a big effect. For example:
• Two candles have a bigger flame than one same sized candle, which
increases the temperature of the gases even quicker. This will create a lower pressure compared to only one candle and the difference (of the pressure) between the inside of the glass and the outside is even greater which will allow more water to get risen.
• The bigger the glass is, the more oxygen the candle will have, but when it extinguishes, there will be more gases cooling down (compared to a smaller glass that only has a little amount of oxygen) which have a better “sucking effect” than less gases
Wrong results: When the experiment was started, just three candles were used (a small, medium and big one). The problem was: After each experiment, the candles became smaller. This had an enormous influence on every result. It is advised to use three candles per size, which leads to slightly different, but correct results. Future possibilities: Various combinations were tried to verify that the author was right on target. Besides trying to make an own candle with three wicks, the only thing, which can be done better the next time, is, to avoid the mistakes that were done in this experiment.
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ACKNOWLEDGEMENTS
I would like to express my sincere gratitude to my physics teacher Mrs Oppel, for her encouragement and tips. Also, would I like to thank my parents who let me spent a lot of money to buy the materials for my experiment as it was for educational purposes. (All tips were reflected during the experiment)
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Discussion During these experiments, there were a few surprises. The biggest surprise started at the beginning of the tests, which was, that the water actually did rise although the author did not expect it. After that, it was found out that the temperature of the water, the amount of candles and the size of the glass, contribute to the significance of the water rising. This caused many wrong results at the beginning of the experiment and led to a lot of confusion. As these factors were recognised early by research as well as by testing, the results noted are absolutely correct and fair.
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References:
Pictures:
• Title: Charles’ Law and the Rising Water Activity3 (Reinforcement Activity)
• Genre: Physics • Link:
http://www.pz.harvard.edu/ucp/curriculum/pressure/s3_reinforcement_charles.pdf
• Author: Unknown (President and Fellows = Harvard Corporation) • Published: 2003 • Pages: 8 • Last access: 15.01.2013
Information:
• Title: Getting the facts right • Genre: Physics • Link:
http://www.math.harvard.edu/~knill/pedagogy/waterexperiment/index.html
• Author: Oliver Knill, 9/24/2006 • Published: 09.12.2006 • Pages: 2 • Last access: 15.01.2013
• Title: How to make water rise • Genre: Science • Link: http://www.wikihow.com/Make-‐Water-‐Rise • Author: uA. • Edited: by Dvortygirl, Krystle, Sondra C, Jonathan E. and 23 others • Published: unknown • Pages: 3 • Last access: 15.01.2013
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• Title: Water rising • Genre: Science • Link: https://docs.google.com/viewer?a=v&q=cache:H6jI-‐
qNV39gJ:www.umanitoba.ca/outreach/crystal/Grade%25205/Cluster%25204/5-‐4-‐03%2520-‐%2520Water%2520Rising%2520-‐%2520Demonstration%2520and%2520Investigation.doc+rising+water+in+glass&hl=en&pid=bl&srcid=ADGEEShECSvx0fYrKGLC8gFtXmOA1-‐G8GvrbDSxJjBLdkT3vLe5Jbd2RlK4WrDhpEjlwiU3lh7KwPdlqdyHd71HJShoZaSBi2Xm2sRaUWMH-‐04gwBlMAEO64q332-‐SGhRhGqyDfFwXWR&sig=AHIEtbS1YEX2QtfZz5O2i9l7FDMTH-‐sSow
• Author: Robert Krampf and Steve Spangle • Published: 2007 • Pages: 3 • Last access: 15.01.2013
