Project bio gas

Science Fair" Projects

I have had a number of enquiries about "Science Fair" projects over the years and several students have won prizes. I recently found out that latex baloons (the stretchy kind) are permeable to gas (more so methane) so you should try to use mylar (silver) balloons for gas storage, or a 'floating drum' (as below).
The following is based on my most recent reply (as I keep changing my suggestions as I think of better ways of making a small digester), but I am still happy to answer further e-mail questions.
If you send me pictures and/or comments of your own project I will add them to this page.
Todd Purcell has provided a File and a (bigger) PowerPoint Presentation.
Here is a Project, that won first prize. The only comment I would make is that calculating the volume of the ballon, using Volume of Shpere = 4/3 Pi r(cubed), would give a better indication of gas production. Well done Adriana! A few people have had problems with latex (stretchy) ballons leaking and I now suggest using "mylar" (silver) balloons, but measuring gas volume may be a challenge.
BrieAnn did not win a prize but her project is good. Here is BrieAnn's PowerPoint Presentation.
Nikki Shaw has won some prizes - visit her page.
This Demonstration was not a "Science Fair" project, but shows what can be done quite cheaply.

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There are plenty of options for anaerobic digesters as all you need is a gas tight container and some organic waste. I think the simplest method is if you can find two buckets/containers such that one will fit upside down inside the other with some clearance (not that easy to do in spite of the proliferation of plastic containers). The bottom container holds the digesting liquid and the inverted one becomes the gas holder - it may need some guides so it does not topple over as it rises with gas. To avoid the possibility of a gas leak I would use waterproof tape/glue/silicon sealant to hold a plastic tube from the top of the gas space running out through the side of the digester bucket (you will notice a liquid leak!) with enough slack to allow the gas holder to rise (See sketch below, 2004 version, guides not shown - a challenge for you!).

I hope by this stage you have read and understood the safety page http://www.adelaide.edu.au/biogas/safety/index.html although it is written with larger digesters in mind - for example you do not have to have the flame 20 m from the digester or have a flame trap, as in the most unlikely event of the flame burning back to the digester you will not get much more of a bang than when lighting a gas stove with such a small digester!
Can you get some cow manure (make sure NO antibiotics are given to the animals) - enough to quarter fill the digester container? I have found that dog manure does not work on its own, like poultry manure or food waste you may still need some cow manure as a starter. Fill the rest of the digester with water and mix it up, then place the gas holder on top and let all the air out (some weight on the gas holder will help). The digester needs to be placed somewhere warm (15-20 C or 60-70 F) and gas production should start in a day or so. Put the free end of the plastic tube in a jar of water to seal it. If you are in a hurry 35-40 C (95-105 F) will give quicker response. Let the gas holder fill up (the volume will probably be a bit less than the volume of liquid, I hope) and discard this gas, as the first gas will be mainly carbon dioxide (CO2) and won't burn (it will actually extinguish a match, but don't allow smoking as there may be some methane present - all being well).
To make a burner you need a small hole for the jet into a larger tube as a mixer, a bit like a bunsen burner as used in chemistry labs, but I do not worry about the air holes. I use a 1 mm hole into 12 mm tube, so a 1/16" jet opening into 1/2" tube (this should be metal) would work well with enough weight to make about 25 mm (1") water pressure - more weight may blow out the flame and less may not give enough gas. About 20 litres (I think that's 5 gallons) of gas will normally boil a cup of water.
You may find that you get a bluish flame when the match is held there, but the flame goes out without the match - that means you have less than 50% methane in the biogas or the pressure is too high, just remove some weight and if the flame still goes out burn off the gas and try again in a few days. As methane is a greenhouse gas try to burn off the excess gas rather than just letting it escape to atmosphere.
You could measure how high the gas container rises each day to record the volume of gas generated and once everything is going well (maybe a week or so) add some more waste (no more than 1/20 of the liquid volume each day) to feed the digester - the overflow is good organic manure.
Here is my 2005 version, made out of soft drink bottles and containing the smell better!

It is a bit hard to see, but the smaller plastic jar inverted in the right hand container is for gas storage and the water level in the inner jar is slightly below that in the outer container. If you look carefully you will see the tube connecting the digester head space (left container) to the gas storage headspace (right container). The tube coming off to the front is the gas outlet. As gas is generated the inverted jar will rise.
The Syringe Protocol provides a cheap method of finding the biogas composition. More than 50% Methane will burn with a stable flame.

Electromagnetism

Main article: Electromagnetism

Magnetic field circles around a current

Ørsted's discovery in 1821 that a magnetic field existed around all sides of a wire carrying an electric current indicated that there was a direct relationship between electricity and magnetism. Moreover, the interaction seemed different from gravitational and electrostatic forces, the two forces of nature then known. The force on the compass needle did not direct it to or away from the current-carrying wire, but acted at right angles to it.^[30] Ørsted's slightly obscure words were that "the electric conflict acts in a revolving manner." The force also depended on the direction of the current, for if the flow was reversed, then the force did too.^[45]
Ørsted did not fully understand his discovery, but he observed the effect was reciprocal: a current exerts a force on a magnet, and a magnetic field exerts a force on a current. The phenomenon was further investigated by Ampère, who discovered that two parallel current-carrying wires exerted a force upon each other: two wires conducting currents in the same direction are attracted to each other, while wires containing currents in opposite directions are forced apart.^[46] The interaction is mediated by the magnetic field each current produces and forms the basis for the international definition of the ampere.^[46]

The electric motor exploits an important effect of electromagnetism: a current through a magnetic field experiences a force at right angles to both the field and current

This relationship between magnetic fields and currents is extremely important, for it led to Michael Faraday's invention of the electric motor in 1821. Faraday's homopolar motor consisted of a permanent magnet sitting in a pool of mercury. A current was allowed through a wire suspended from a pivot above the magnet and dipped into the mercury. The magnet exerted a tangential force on the wire, making it circle around the magnet for as long as the current was maintained.^[47]
Experimentation by Faraday in 1831 revealed that a wire moving perpendicular to a magnetic field developed a potential difference between its ends. Further analysis of this process, known as electromagnetic induction, enabled him to state the principle, now known as Faraday's law of induction, that the potential difference induced in a closed circuit is proportional to the rate of change of magnetic flux through the loop. Exploitation of this discovery enabled him to invent the first electrical generator in 1831, in which he converted the mechanical energy of a rotating copper disc to electrical energy.^[47] Faraday's disc was inefficient and of no use as a practical generator, but it showed the possibility of generating electric power using magnetism, a possibility that would be taken up by those that followed on from his work.
Faraday's and Ampère's work showed that a time-varying magnetic field acted as a source of an electric field, and a time-varying electric field was a source of a magnetic field. Thus, when either field is changing in time, then a field of the other is necessarily induced.^[48] Such a phenomenon has the properties of a wave, and is naturally referred to as an electromagnetic wave. Electromagnetic waves were analysed theoretically by James Clerk Maxwell in 1864. Maxwell developed a set of equations that could unambiguously describe the interrelationship between electric field, magnetic field, electric charge, and electric current. He could moreover prove that such a wave would necessarily travel at the speed of light, and thus light itself was a form of electromagnetic radiation. Maxwell's Laws, which unify light, fields, and charge are one of the great milestones of theoretical physics.^[48]

Electric circuits

Main article: Electric circuit

A basic electric circuit. The voltage source V on the left drives a current I around the circuit, delivering electrical energy into the resistor R. From the resistor, the current returns to the source, completing the circuit.

An electric circuit is an interconnection of electric components such that electric charge is made to flow along a closed path (a circuit), usually to perform some useful task.
The components in an electric circuit can take many forms, which can include elements such as resistors, capacitors, switches, transformers and electronics. Electronic circuits contain active components, usually semiconductors, and typically exhibit non-linear behaviour, requiring complex analysis. The simplest electric components are those that are termed passive and linear: while they may temporarily store energy, they contain no sources of it, and exhibit linear responses to stimuli.^[49]
The resistor is perhaps the simplest of passive circuit elements: as its name suggests, it resists the current through it, dissipating its energy as heat. The resistance is a consequence of the motion of charge through a conductor: in metals, for example, resistance is primarily due to collisions between electrons and ions. Ohm's law is a basic law of circuit theory, stating that the current passing through a resistance is directly proportional to the potential difference across it. The resistance of most materials is relatively constant over a range of temperatures and currents; materials under these conditions are known as 'ohmic'. The ohm, the unit of resistance, was named in honour of Georg Ohm, and is symbolised by the Greek letter Ω. 1 Ω is the resistance that will produce a potential difference of one volt in response to a current of one amp.^[49]
The capacitor is a device capable of storing charge, and thereby storing electrical energy in the resulting field. Conceptually, it consists of two conducting plates separated by a thin insulating layer; in practice, thin metal foils are coiled together, increasing the surface area per unit volume and therefore the capacitance. The unit of capacitance is the farad, named after Michael Faraday, and given the symbol F: one farad is the capacitance that develops a potential difference of one volt when it stores a charge of one coulomb. A capacitor connected to a voltage supply initially causes a current as it accumulates charge; this current will however decay in time as the capacitor fills, eventually falling to zero. A capacitor will therefore not permit a steady state current, but instead blocks it.^[49]
The inductor is a conductor, usually a coil of wire, that stores energy in a magnetic field in response to the current through it. When the current changes, the magnetic field does too, inducing a voltage between the ends of the conductor. The induced voltage is proportional to the time rate of change of the current. The constant of proportionality is termed the inductance. The unit of inductance is the henry, named after Joseph Henry, a contemporary of Faraday. One henry is the inductance that will induce a potential difference of one volt if the current through it changes at a rate of one ampere per second.^[49] The inductor's behaviour is in some regards converse to that of the capacitor: it will freely allow an unchanging current, but opposes a rapidly changing one.

The Strength of an Electromagnet

Abstract Electric charges in motion create magnetic fields. You can create an electromagnet with a simple coil of wire and a battery. This project has ideas for exploring how the strength of the electromagnet depends on the size of the coil or the voltage supplied to it. Objective The goal of this project is to investigate the strength of an electromagnet made from a coil of wire. How does the strength of the magnetic field change as the number of turns in the coil is increased? Introduction An electric current flowing in a wire creates a magnetic field. You can prove this to yourself with a magnetic compass (see the Science Buddies project idea Using a Magnet as an Electrical Current Detector). The magnetic field around a straight wire is not very strong. However, if the wire is wrapped in a coil, the fields produced in each turn of the coil add up to create a stronger magnetic field (see Figure 1). Figure 1. The green lines show the magnetic field surrounding a coil through which electric current is flowing. The right-hand rule tells you the direction of the magnetic field produced by electric current. In the case of a single wire, when you hold your right hand so that the thumb points in the direction of the current flow, your fingers curl in the direction of the magnetic field (see Figure 2). Figure 2. Illustration of the right-hand rule for a single wire. For a coil of wire, when the fingers of your right hand curl in the direction of the current flow, your thumb points toward the north pole of the magnetic field created by the coil (see Figure 3). Figure 3. Illustration of the right-hand rule for a coil of wire through which an electric current is flowing. In this project, you will investigate how the strength of the magnetic field produced by a coil of wire changes when the number of turns in the coil are changed. You will also investigate which orientation of the coil is more effective: holding the coil parallel to the material to be picked up, or holding the coil perpendicular to the material. Terms, Concepts, and Questions to Start Background Research To do this project, you should do research that enables you to understand the following terms and concepts: electromagnet, right hand rule. Questions Can you think of a way to demonstrate which end of your coil is N and which is S? What happens to N and S if you reverse the connections to the battery? Bibliography Brain, M., 2006. "How Electromagnets Work," HowStuffWorks.com [accessed July 18, 2006] http://www.howstuffworks.com/electromagnet.htm. Thomas Jefferson National Accelerator Facility - Office of Science Education, date unknown. "What Is an Electromagnet?" [accessed July 18, 2006] http://education.jlab.org/qa/electromagnet_is.html. Nave, C.R., 2006. "Magnets and Electromagnets," HyperPhysics, Department of Physics and Astronomy, Georgia State University [accessed July 18, 2006] http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/elemag.html. Materials and Equipment To do this experiment you will need the following materials and equipment: 6 V lantern battery (e.g., Radio Shack 23-016 or 23-560), magnet wire (e.g., Radio Shack #278-1345), alligator clip leads (e.g., Radio Shack #278-1156), sharp knife for stripping magnet wire, masking tape, box of steel paper clips, 100–200 steel washers (approx. 1 cm diameter), three identical pieces of iron for the core material, for example: iron nails, iron bolts, or short lengths of iron pipe. Whatever you choose for the core material, all three pieces should be the same size. optional (for Variations 1 and 2, below): paper for making coil forms. Experimental Procedure Note Before Beginning: This science fair project requires you to hook up one or more devices in an electrical circuit. Basic help can be found in the Electronics Primer. However, if you don't have experience in putting together electrical circuits you may find it helpful to have someone who can answer questions and help you troubleshoot if your project isn't working. A science teacher or parent may be a good resource. If you need to find another mentor, try asking a local electrician, electrical engineer, or person whose hobbies involve building things like model airplanes, trains, or cars. You may also need to work your way up to this project by starting with an electronics project that has a lower level of difficulty. You will make three different electromagnets, using three identical pieces of core material. Each coil will have a different number of turns. For example, you could try 100, 200, and 500 turns. Wrap the magnet wire neatly around the core material. Here are some tips to make wrapping easier. Leave 5–6 cm of wire free at each end of the coil for making the connection to the battery. Make a holder for the spool of magnet wire, so that you can roll the wire right off of the spool. For example, you can stick a pen or pencil through the spool, and tape it down to a couple of small boxes. Use a small piece of tape to attach the wire to the core material, about 0.5–1 cm in from the end. Turn the core to unwind the magnet wire from the suspended spool. Use your fingers to keep the wire tight against the core material. Wrap each successive turn so that the wire lines up neatly. Keep track of the turns (each time the tape that holds the wire in place comes around). This is easier if you can recruit a helper to make tally marks for you. When you reach the desired number of turns, again tape the wire to the coil form, and cut it off. Leave 5–6 cm of free wire for making the connection to the battery. Particularly for the larger coils, you will need to wrap multiple layers of wire to get the desired number of turns. Use the utility knife to carefully scrape off the enamel insulation from the magnet wire over a 1 cm length at each end. You'll see the shiny copper wire underneath. Be careful not to cut the wire. Place the paper clips (or washers) in a shallow container (slightly longer than the coil). You will probably find that paper clips work well for coils with an air core, and washers work well for coils with an iron or steel core. Pick up paper clips with the coil held parallel to the container. Use the clip leads to connect the coil to the battery. Touch the coil (lengthwise) to the paper clips (or washers), then pull the coil away from the tray. Disconnect the coil from the battery, and count how many paper clips (washers) were picked up. Record the number in your lab notebook. Organize your data in a table like the one below. Repeat at least five times for each coil. Pick up paper clips with the coil held perpendicular to the battery. Use the clip leads to connect the coil to the battery. This time touch the core material to the paper clips (or washers), then pull the coil away from the tray. (In other words, this time the coil will be perpendicular to the tray of paper clips.) Disconnect the coil from the battery, and count how many paper clips (washers) were picked up. Record the number in your lab notebook. Organize your data in a table like the one below. Repeat at least five times for each coil. Calculate the average number of paper clips (washers) lifted by each coil for each method (see the table below). Number of Turns Number of Paper Clips Picked Up Coil Parallel to Paper Clips Coil Perpendicular to Paper Clips Trial Average Trial Average 1 2 3 4 5 1 2 3 4 5 100 200 500 Make a graph of the results. Plot the number of paper clips picked up for each coil orientation (y-axis) vs. number of turns in the coil (x-axis). Variations Try using different metals as core materials inside the coil. For example, steel, copper, aluminum, etc. You can use nails, bolts, pipe, tubing, etc. For making comparisons, it would be ideal to have core materials that are the same diameter and weight. You can wrap the coils directly around the core materials as described above, or you can make a single coil (for each number of turns that you want to test) and test it with different core materials inside. Here is a procedure for making coils so that you can swap the core material: Make a coil form by wrapping several layers of paper around a sample of your core material. Use enough layers of paper or cardboard so that the coil form will hold its shape. Tape the paper, then slide it off the cylinder form. Test the coil form with each of the core materials to make sure that they all fit. Wrap your coil around the coil form, as described above. Now you will be able to slide different core materials in and out of the coil. You can leave the paper material in place. You could also try another experiment to see if removing the paper makes any difference in the strength of the electromagnet. Test the coils both with and without the paper material inside. As in the procedure above, you can compare the amount of weight that electromagnets with different core materials can lift. What happens when you change the distance between the coil of wire and a metal core material? For example, increase the diameter of your core forms (described in Variation #1, above) by 2, 5, 10, and 20 mm. For an interesting addition to your display board, you can map the shape of the magnetic field produced by your electromagnets. Here's how: Mapping Magnetic Fields. What happens when you change the voltage applied across the coil? You can connect 2 or 3 lantern batteries in series, or use increasing numbers of D-cell batteries in series. As above, measure how many paper clips (or washers) you can lift with a coil at each voltage. For more science project ideas in this area of science, see Electricity & Electronics Project Ideas.

Magnet Levitation 2

Magnet Levitation: 
The fact that same magnetic poles repel each other is the base for design of many industrial equipments. Repelling magnets are often part of another electrical or mechanical system. When you attempt to move the North pole of one magnet toward the North pole of another magnet, initially the other magnet may be pushed away, but soon it flips over and the South pole of that face and attract your magnet.
Many studies have been done on levitating objects with magnetic force, however it is now proven that 100% levitation for a non moving object is impossible. Partial levitation is now used in construction of high speed magnetic trains. Many other instruments and equipment also use repelling properties of magnets.
Following are some of the projects that can be made using magnets with same poles facing each other. They are all applications of magnet levitation.
Floating Rings:
In this project you will make a set of magnet rings to float above each other while their balance is maintained using a wood dowel. You will then examine the flexibility of the floating rings and propose uses for such a floating set of rings.
Material:
You will need a base board, a 6" wood dowel or pencil and six ring ceramic magnets, make sure that the wood dowel or pencil fits the hole in the center of magnets. Also try to get painted magnets. A layer of paint will protect ceramic magnets from chipping.
Procedure:
Mount the pencil or wood dowel vertically in the center of the base board. If you use glue, you will need to wait a few hours until the glue is fully dry. Place the first ring magnet over the wood dowel and let it go down. Get a second magnet and bring it close to the first magnet to feel the magnetic forces and find out which two poles repel each other. Then insert this magnet in a way that when it gets to the first magnet, same poles are faced each other and two magnets will repel. So the second magnet will float. 

Continue these steps with the other four magnets. Finally you will have 6 ceramic ring magnets on a column that can freely move up and down, but gravity force is not able to pull them down because the same poles of magnets are facing each other. Push the upper magnet down. How much force do you need to put all magnets together? Now release it. What happens? Why? Can you use this magnet levitation model to make other products?

Magnetic Spring Scale: One of the ideas have been a magnetic spring scale. As you see a clear plastic tube is placed above the upper magnet. Then another plastic tray is placed above the plastic tube. You may use a paper tube and a paper tray instead. When weight is placed on the tray, the tray goes down. The amount that it moves depends on the amount of weight. A piece of paper is used as the indicator hand. Also a Popsicle stick is used to mark the weight. As you see most of the material can be replaced by other material that you may have around your home.

Age group:
This is a good science project for ages 6 to 13.
 

Magnetic Levitating Train project

Magnet Levitation
If you have learned about magnets and magnetic poles, you may want to demonstrate one of the practical applications of repelling poles as your science project. You can make a magnetic levitating train. In a magnetic levitating train the rails and the train must repel each other.

The main component of this magnetic levitating train is a strip of strong plastic magnet. One pair of the plastic magnet will be glued to a board and act as the rail. Two smaller strips will be glued to the train car (Instead of wheels). Plastic magnets are available online.

You may also buy a kit that contains all materials. Magnet Levitation Science set contains the materials you need to perform many different experiments related to magnet and magnetic field. These materials can also be used in your presentations or as a part of your display.  Learn about equilibrium and magnetic fields while building a gravity-defying train.

The instructions are provided online so you will always receive the latest instructions. The specific web address included in your kit directs you to the instruction page.

Experiments in this kit include: * Magnetic Levitating Train * Floating Rings * Print the magnetic field * Magnet Suspension Apparatus

Magnet Levitation online instructions includes several introductory experiments in magnetism as well as five complete levitation projects. Magnet Levitation kit includes:

• 20 Ceramic Magnets
• Super-strong NEODYMIUM Magnet
• Hi-force Magnetic Strips
• Plastic Guide Rails
• Compass
• Iron Filings
• Wood Block
• Wooden dowel
• Online instructions

Additional Materials Required: Additional Materials Required for your experiments can be found at home or purchased locally. Some of these material are:

Clear adhesive tape String/tread 1 book 1 Nickel (US five cent piece) 1 US dollar bill 5 US pennies 6 Small paper clips Several Magazines 1 piece of paper (8.5 x 11) lightweight tape 2 US quarters sheet of sandpaper

Initial levitating train you build looks like this picture. You may want to build and paint a decorative train to mount above your plain train block.

Opportunities for Science Fair Projects
Many of the questions asked in the Magnet Levitation Projects, can serve as the "Problem to be solved" in a science project. In setting up your project, you would first state the problem, then hypothesis, (a guess as the answer to your problem), next you will write a procedure to check the hypothesis, and finally after you do your experiments, you draw a conclusion that answers the stated problem based on what you actually observe in your research. In addition you may be interested in proposing your own, specific research that will expand on your conclusion.
Since magnets are visually enticing in themselves as they interact with each other, it would be strongly suggested that your presentation include the apparatus you used in your research.

 

Make a Battery from Potato

Make a Battery from Potato
Introduction:
Batteries generate electricity through a chemical reaction between two different electrodes and one electrolyte. Use of Copper and Zinc electrodes and Sulfuric acid as electrolyte is a proven method for this process. We are wondering if we can use any other liquid as electrolyte? This gave us the idea of using a potato as electrolyte. After all a fresh potato has a lot of juice that may serve our purpose as electrolyte.
Problem:
Can Potato be used to generate electricity?
Hypothesis:
Potato juice contains many water soluble chemicals that may cause a chemical reaction with one or both of our electrodes. So we may get some electricity from that.
 

Material: For this experiment we use: A fresh potato Copper Electrode Zinc Electrode A Digital or Analog Multimeter to measure Voltage or Current of produced electricity. Alligator clips/ Leads

Procedure:
We insert copper and zinc electrodes in to the potato, close but not touching each other. We use Clip leads to connect our electrodes to the Multimeter to measure voltage between two electrodes or current passing through the multimeter. For this experiment we removed the shell of a broken AA battery for our Zinc electrode. (Make sure to test your multimeter by connecting it's Positive and Negative wires to each other that should show no current and no voltage).
 

Record And Analyze Data:

A digital multimeter showed 1.2 volts between the electrodes, but the analog multimeter showed a much smaller value. In other words even though the voltage between electrodes is 1.2 Volts, the speed of production of electricity is not high enough for an analog multimeter to show the exact voltage. (Analog multimeter gets it's power from our potato to show the voltage, but digital Multimeter gets it's power from an internal battery and does not consume any of the electricity produced by our potato, that is why it shows a larger and more accurate value). We repeated this experiment with some other fruits and all resulted almost the same. In all cases the produced voltage is between 1 and 1.5 volts, and in all cases they do not produce enough current to turn on a small light.

Another thing that we learned from this experiment is that creating electricity and making a battery is easy, the main challenge is producing a battery that can continue to produce larger amount of electricity for larger amount of time. potato plate 2 pennies 2 galvanized nails three 8 inch lengths insulated copper wire, each with 2 inches of the insulation stripped off one end digital clock with attachments for wires First, cut a potato in half and put the two halves on a plate so they stand on their flat ends. The plate is there to keep your table clean. Then, wrap the end of one piece of wire around a galvanized nail and wrap the end of a second piece of wire around a penny. Stick the nail and penny into one half of the potato so that they're not touching each other. Next, wrap the third piece of wire around the other penny and put it into the other half of the potato. Put the other nail into the second half of the potato, but this nail should not have wire wrapped around it. Now, connect the wire from the penny on the first half of the potato to the nail that has no wire on it in the second half of the potato. Finally, touch the free ends of the wires to the wires coming out of the digital clock. Does it work? You'll probably have to try connecting the wires to the clock in different ways to get the energy to flow through the clock in the right direction. It's just like putting batteries into a clock; they have to go in the right way.

The Effect of Salt on the Boiling Temperature of Water

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INITIAL OBSERVATION

Cooking instructions tell you to add salt to water before boiling it.

PROJECT TITLE

The Effect of Salt on the Boiling Temperature of Water

PURPOSE OF THE PROJECT

To find out how table salt affects the boiling temperature of water.

HYPOTHESIS

Adding table salt to boiling water will cause the water to boil at a higher temperature.

MATERIALS AND EQUIPMENT

• Table Salt
• Distilled Water
• 2 Quart Cooking Pot
• Pint measuring cup
• Teaspoon and tablespoon measuring spoons
• Thermometer
• Stirring spoon

EXPERIMENTAL PROCEDURE

1. Boil one quart of distilled water on a stove.
2. Measure the temperature of the boiling water. Record the highest temperature reading. This is the control to compare with.
3. Measure out table salt using a kitchen measuring spoon. Level the spoonful.
4. Add the measured salt to the boiling water and stir.
5. Measure the temperature of the boiling water with the salt in it. Record the highest temperature reading.
6. Repeat for other amounts of salt.

DATA

Data Obtained: 2/25/95, Mankato, MN

Amount of boiling water	2 Cups
Temperature of boiling water (Control)	212.9°F
Amount of table salt added to boiling water: Run #1	1 Tbl.
Temperature of boiling water after adding salt: Run #1	215.6°F
Additional amount of table salt added to boiling water: Run #2	1 Tbl.
Temperature of boiling water after adding salt: Run #2	218.3°F

EXPERIMENTAL OBSERVATIONS

When the salt was added to boiling water it bubbled up more, and then stopped boiling. Shortly afterwards, it boiled again.
If the thermometer extends beyond the outside of the pot it reads a higher temperature. Heat from the stove burner makes the thermometer read higher. Keep the thermometer over the pot when making temperature measurements.

CALCULATIONS

• Total amount of table salt added for Run #1:  0 + 1 = 1 Tbl.
• Total amount of table salt added for Run #2:  1 + 1 = 2 Tbl.

RESULTS

Temperature of boiling water (Control)	212.9°F
Amount of table salt added to boiling water: Run #1	1 Tbl.
Temperature of boiling water after adding salt: Run #1	215.6°F
Total amount of table salt added to boiling water: Run #2	2 Tbl.
Temperature of boiling water after adding salt: Run #2	218.3°F

 

Amount of Table Salt Added Versus
Water Boiling Temperature

CONCLUSIONS

• Is the hypothesis correct?
  Yes. Adding table salt to water causes the water to boil at a higher temperature.
• Problems with doing the experiments.
  The temperature readings were hard to make. Gloves had to be worn to keep my hands from getting too hot. Had to be careful that the stove heat was not hitting the thermometer.
• Other things learned.
  Be careful when adding salt to boiling water. It makes the water boil vigorously for a second or two.

Battery Power

Introduction In my project I was trying to find out what battery lasts the longest. I will also try to determine if the cost of the battery has anything to do with the power it has.

Hypothesis I think the Duracell battery will last the longest. I also believe that the more expensive the battery the longer it will last.

Materials paper, wires, stop watch, battery holders, metal connectors, computer, light bulbs, and graph paper. Batteries - Duracell, Everready, Energizer, and BA 30 "Army batteries."

Research/Sources of Information I researched on how a battery produces electricity. The battery is a dry cell. A chemical reaction between the electrolyte and the zinc electrode helps produce electricity.

Vocabulary Electrodes - The negative or positive part of an electric cell. Electrolyte - A liquid or moist substance that conducts electricity. Dry Cell - An electrical cell that has a moist electrolyte. Terminal - The negative or positive end of an electrolyte.

Experiment I experimented by testing the power of four different brands of batteries. I did this by hooking up the batteries to a light bulb. I then kept track of the length of time each bulb stayed lit. I tested two batteries from each of the four brands.

Results After the testing was completed the following results were recorded: The Duracell battery lasted the longest, 101 hours and 20 minutes; Energizer battery, second, 99 hours and 17 minutes; Eveready battery, third, 28 hours and 30 minutes, and last but not least was the BA 30 batteries, 25 hours ad 58 minutes.

Wooden Generator Science Project 3

Wooden Generator
Science Project

An electric generator is a device that converts mechanical energy to electrical energy. In a generator, a moving magnet will push the free electrons in a conductor back and forth. Movements of electrons along a conductor are called electricity. Since in this type of electricity electrons swing back and forth, we also call it alternative electricity and show it with symbol AC. Home electricity is an AC electricity with frequency of about 50 Hertz; In other words, electrons swing back and fort 50 times per second.

Many students like to make an electric generator as their science project; however, the more they learn about the complex structure of commercial electric generators, the more they discourage. Even the simplest electric generators seem impossible to make with limited materials, tools and skills available to students.

What is a wooden generator?

Wooden generator is a simple and easy to understand design that students can use to make an electric generator. In a wooden generator, the main structure is made of wood. The only non wooden parts are the magnet and the wire. This design was originally prepared by ScienceProject.com and made available to their members. The first students who tried this project had difficulties in cutting the woods and finding the right size wire and magnet.  Later MiniScience.com offered a kit for this project with pre-cut woods and other hard to find materials.

The instructions in this page is a combination of instructions published by ScienceProject.com and instructions published by MiniScience.com Published with permission.

How to start?

To make an electric generator you must first gather the materials. If you want to buy a kit, you can search the Internet for wooden generator and order a kit online. If you want to buy the materials locally, start with wire, magnet, and light bulb receptacle. Check all the prices before you buy anything and make sure they will not exceed your budget. Also consider the fact that sometimes purchasing parts one by one may cost many times more than a kit. When all the materials are ready and wooden parts are cut to size, you still need 2 or 3 days to complete your project. In 2 different steps you will need to wait for glue to dry before you be able to continue.

List of materials: 250 feet magnet wire AWG 23 Cow magnet 3" x 1/2" Low voltage miniature light bulb Miniature receptacle Piece of wood dowel with 1" outer diameter Piece of wood dowel with 3/8" O.D. 2 pieces of 3 1/2" x 3 1/2" wooden squares with 3/8" hole in center. 4 pieces of 1" x 3 1/2" wooden rectangles Piece of sand paper Wood glue or white glue

If you are buying a kit, all the wooden parts are included and they are already cut to the size. So you just need to connect them. If you don't have a kit, prepare the wooden parts before going to the next step. You will need some wood working tools and skills for this.
Put them together 

Now that all your parts and materials are ready, you can start putting them together. STEP 1: Start with one square and one rectangle. Apply some wood glue to the bottom side of one of the rectangles and attach it to one side of the square piece.

STEP 2: Now, take another rectangles and apply some wood glue to the bottom and one side of the rectangle. Now, properly place it on the square as shown on the image to the right. This piece should glue to the large square and the previous rectangle when done correctly.

STEP 3: Take a third rectangle and apply some glue to the bottom and one side of the rectangle. Place it on the square as shown in the picture in the right. This piece should glue to one side of the large square and the previous rectangle when done correctly.

STEP 4: Apply some glue to the bottom and one side of the last rectangle and complete your box. Make final adjustments while your box is on a flat surface. Apply additional glue to the corners if needed. Make sure the rectangles are as close as possible to the edges of the square piece. This will give enough space for magnet to spin freely.

Temporarily place the other large square on the top and place a weight on it. A small cup can be used as a weight. Do one more final adjustment if needed. Make sure that the temporary large square will not stick to the rest of the box at this time. Wait about two hours for the glue to dry. (Prevent excess glue, or place a piece of 4" x 4" paper between the box and temporary large square)

Prepare the wood dowel Cut a 3/4" piece from the 1" wood dowel. Make a 3/8" hole in the center of it. Insert a 6" long 3/8" wood dowel in the hole, apply some glue. center it and wait for the glue to dry.  Make another hole with the diameter of your rod magnet in the center of the larger wood dowel piece for the magnet to go through. Wood dowels after completing the step 1 Wood dowels after completing the step 2

STEP 5: Insert the magnet in the hole of the wooden dowel as shown in the picture to the right. Center it and use some glue to secure it. When inserting the magnet, hold the thick part of the wooden dowel to protect it from breaking. The magnet and wooden dowel together will form the rotor for your electric generator.

STEP 6: Insert the wooden dowel into the hole at the center of the square box that you have constructed. At this time the magnet should be inside the box.

STEP 7: To complete the box, place the other large square on top of the other square so that the wooden dowel extends out of the hole at the top of the square. So that the square will be permanently attached to the box, apply some glue to the edges of the square and wait for the glue to dry. You now have a box with a magnet that can turn both clock and counter clockwise when you spin the extended part of the wooden dowel.

The final box should look similar to the picture to the right.

STEP 8: The stator is about 300 loops of continuous insulated wire that you wrap around the box, close to the center.

Leave about one foot of the magnet wire and then proceed to wrap the magnet wire around the box. Be sure to begin wrapping at least 1 foot in from the beginning of the wire or else you will run into a problem later on. Wrap the wire loosely so that the box will not be crushed. Be sure to wrap the wire at least 280 time or more. 300 turns is the average. More wire in the coil results in more electricity and a more powerful generator.  When the magnet wire is finished, leave another one foot wire unwrapped at the other end just as you did in the beginning of the wire.

Twist the two ends of the wire so the wire does not unwind. You may also use some masking tape to keep the wires in place. Note that the wire has an invisible insulation, so coppers are not touching each other when you wrap them or twist them over each other.

STEP 9: Remove about one inch of the insulation off the two ends of the wire coil. Insulation can be removed using a sand paper or any other sharp object. Bare copper wire has a distinct metallic color that will be observed after you remove the insulation.

Connect the two ends to the two screws of the bulb holder. To do this you must first loosen the screws, place the bare wire under the screws, and then tighten the screws.  Screw the light bulb on the base. TEST YOUR WOODEN GENERATOR! You are finally done with your wooden generator. The final product should look somewhat like the image to the right. To test your wooden generator, spin the axis (wooden dowel) quickly to see the light.

When you spin the dowel by hand, you must do it as fast as you can in order for the light.  You can also try spinning it faster by using an electric drill, however, doing this might spin it so fast that your light bulb may possibly burn.  When your generator is ready, you can use it for additional experiments. Following are some of the project ideas you may perform with this generator:

How does the speed of rotor affect the produced voltage? How does the number of windings on the stator affect the produced voltage? How does the wire gauge affect the production of electricity?

Question: Where can I buy magnet wire and magnet?
Answer: Search the Internet for wooden generator. Companies who sell wooden generator kit usually sell all the materials separately as well. 

How Electric Motors and Generators Work

Learn How They Generate Power for Electric Cars & Hybrids

Simple electric generator: Electricity is induced in the coil as it cuts through the magnetic field.

Electric vehicles rely exclusively on electric motors for propulsion, and hybrids use electric motors to assist their internal combustion engines for locomotion. But that's not all. These very motors can be, and are, used to generate electricity (through the process of regenerative braking) for charging these vehicles' onboard batteries. The most common question is: "How can that be ... how does that work?" Most folks understand that a motor is powered by electricity to do work—they see it everyday in their household appliances (washing machines, vacuum cleaners, food processors). But the idea that a motor can "run backwards," actually generating electricity rather than consuming it seems almost like magic. But once the relationship between magnets and electricity (electromagnetism) and the concept of conservation of energy is understood, the mystery disappears.

Electromagnetism

Motor power and electricity generation begin with the property of electromagnetism—the physical relationship between a magnet and electricity. An electromagnet is a device that acts like a magnet, but its magnetic force is manifested and controlled by electricity. When wire made of conducting material (copper, for example) moves through a magnetic field, current is created in the wire (a rudimentary generator). Conversely, when electricity is passed through a wire that is wound around an iron core, and this core is in the presence of a magnetic field, it will move and twist (a very basic motor).

Motor/Generators

Motor/generators are really one device that can run in two opposite modes. Contrary to what folks sometimes think, that does not mean that the two modes of the motor/generator run backwards from each other (that as a motor the device turns in one direction and as a generator, it turns the opposite direction). The shaft always spins the same way. The "change of direction" is in the flow of electricity. As a motor it consumes electricity (flows in) to make mechanical power, and as a generator, it consumes mechanical power to produce electricity (flows out).

Electromechanical Rotation

Electric motor/generators are generally one of two types, either AC (Alternating Current) or DC (Direct Current) and those designations are indicative of the type of electricity that they consume and generate. Without getting into too much detail and clouding the issue, this is the difference: AC current changes direction (alternates) as it flows through a circuit. DC currents flows uni-directionally (stays the same) as it goes through a circuit. The type of current utilized is concerned mostly with the cost of the unit and its efficiency (An AC motor/generator is generally more expensive, but is also much more efficient). Suffice it to say that most hybrids and many larger all-electric vehicles use AC motor/generators—so that is the type we'll focus on in this explanation.

An AC Motor/Generator Consists of 4 Main Parts:

• A shaft-mounted wire wound armature (rotor)
• A field of magnets that induce electrical energy stacked side-by-side in a housing (stator)
• Slip rings that carry the AC current to/from the armature
• Brushes that contact the slip rings and transfer current to/from the electrical circuit

The AC Generator in Action

The armature is driven by a mechanical source of power (for example, in commercial electric power production it would be a steam turbine). As this wound rotor spins, its wire coil passes over the permanent magnets in the stator and an electric current is created in the wires of the armature. But because each individual loop in the coil passes first the north pole then the south pole of each magnet sequentially as it rotates on its axis, the induced current continually, and rapidly, changes direction. Each change of direction is called a cycle, and it is measured in cycles-per-second or hertz (Hz). In the United States, the cycle rate is 60 Hz (60 times per second), while in most other developed parts of the world it is 50 Hz. Individual slip rings are fitted to each of the two ends of the rotor's wire loop to provide a path for the current to leave the armature. Brushes (which are actually carbon contacts) ride against the slip rings and complete the path for the current into the circuit to which the generator is attached.

The AC Motor in Action

Motor action (supplying mechanical power) is in essence the reverse of generator action. Instead of spinning the armature to make electricity, current is fed by a circuit, through the brushes and slip rings and into the armature. This current flowing through the coil wound rotor (armature) turns it into an electromagnet. The permanent magnets in the stator repel this electromagnetic force causing the armature to spin. As long as electricity flows through the circuit, the motor will run.

Electricity for powering our homes

Electricity for powering our homes is made in power stations.
A power station contains large machines called turbines, which are turned very quickly.
Power stations need large amounts of energy to turn the turbines. Most use heat energy produced from burning coal. Others use wind energy or moving water. The spinning turbine causes large magnets to turn within wire coils - these are the generators. The moving magnets within the coil of wire causes the electrons (charged particles) to move within the coil of wire. This is electricity.
Steam turbine generators, gas turbine generators, diesel engine generators, alternate energy systems (except photovoltaics), even nuclear power plants all operate on the same principle - magnets plus copper wire plus motion equals electric current. The electricity produced is the same, regardless of source.

Electricity generation - whether from fossil fuels, nuclear, renewable fuels, or other sources - is based on the fact that:
Electricity is a basic part of our life and it is one of our most widely used forms of energy. We get electricity, which is a secondary energy source, from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources.