I had improved in Term 3 as compared to Term 1 and 2. I learnt many things like the kinetic particle theory, forces, weight,density, mass, scientists' tools, flames and measurement. I also learnt how to draw a graph and also a straight line graph. In practical, we did experiments on flames, measurement of length and time, density of object, elements, compound and mixtures, separation techniques, inside cell and photosynthesis and respiration carried out by plants.
I find that the practical lessons made me like science as it is very fun and I can test theories with with my friends. I hope that I can continue to do more experiments to have more interest in science. To improve my grades, I can revise my work more and practice more.
Sunday, September 26, 2010
Difference between Mass and Weight
Mass is defined as the amount of matter an object has. However, the weight of an object on earth depends on the force of attraction (gravity) between the object and earth. In one of the more common definitions, the weight of an object, often denoted by W, is defined as being equal to the force exerted on it by gravity. This force is the product of the mass m of the object and the local gravitational acceleration g. Expressed in a formula: W = mg
An equipment used to measure the mass of an object is the scale or the beam balance.
An equipment used to measure the weight of an object is the spring balance or the compression balance.
The mass of object is constant everywhere while he weight of an object changes from place to place.
The SI unit for mass is kilogram while the SI unit for weight is Newton.
An equipment used to measure the mass of an object is the scale or the beam balance.
An equipment used to measure the weight of an object is the spring balance or the compression balance.
The mass of object is constant everywhere while he weight of an object changes from place to place.
The SI unit for mass is kilogram while the SI unit for weight is Newton.
Thursday, September 9, 2010
Forming compounds
My friends and I did an experiment to investigate the formation of compounds by reacting two elements, reacting an element and a compound and reacting two compounds. The experiment needs magnesium ribbon, iron filings, dilute sulfuric acid, lead (II) nitrate solution, sodium chloride, test –tube, Bunsen burner, evaporating dish, test-tube holder and a pair of tongs.
Reacting two elements
1. Hold a magnesium ribbon with a pair of tongs. Place it in the Bunsen flame. When the magnesium ribbon catches fire, hold the pair of tongs above the evaporating dish to collect the ashes formed. The magnesium ribbon burned with a bright white light.
2. The ash is white in colour.
3. A new substance has formed because the physical appearance has changed from silvery grey to white in colour and heat is also involved in this reaction.
4. Oxygen has combined with magnesium to form a compound.
5. Magnesium + oxygen = magnesium oxide
Reacting an element with a compound
1. Place half a spatula of iron filings in a test-tube.
2. Add dilute sulfuric acid to a depth of about 2 cm. Effervescence of colourless, odourless gas is seen.
3. A new substance has formed because the test-tube felt warm indicating that heat has been released and the colour of the substance also changed to light grey.
4. Iron + Sulfuric acid = iron sulfate + hydrogen gas
Reacting two compounds
1. Place sodium chloride solution in a test-tube to a depth of about 2 cm.
2. Using a dropper, add lead (II) nitrate solution slowly to the test-tube. White precipitate can be seen.
3. Sodium chloride + lead (II) nitrate = sodium nitrate + lead (II) chloride
Metals have high boiling and melting point where as non-metals have low boiling and melting point. Metals form oxides that are basic while non-metal form oxides that are acidic. Metals are solid at room temperature while non-metal are solids, liquids or gases at room temperature.
Reacting two elements
1. Hold a magnesium ribbon with a pair of tongs. Place it in the Bunsen flame. When the magnesium ribbon catches fire, hold the pair of tongs above the evaporating dish to collect the ashes formed. The magnesium ribbon burned with a bright white light.
2. The ash is white in colour.
3. A new substance has formed because the physical appearance has changed from silvery grey to white in colour and heat is also involved in this reaction.
4. Oxygen has combined with magnesium to form a compound.
5. Magnesium + oxygen = magnesium oxide
Reacting an element with a compound
1. Place half a spatula of iron filings in a test-tube.
2. Add dilute sulfuric acid to a depth of about 2 cm. Effervescence of colourless, odourless gas is seen.
3. A new substance has formed because the test-tube felt warm indicating that heat has been released and the colour of the substance also changed to light grey.
4. Iron + Sulfuric acid = iron sulfate + hydrogen gas
Reacting two compounds
1. Place sodium chloride solution in a test-tube to a depth of about 2 cm.
2. Using a dropper, add lead (II) nitrate solution slowly to the test-tube. White precipitate can be seen.
3. Sodium chloride + lead (II) nitrate = sodium nitrate + lead (II) chloride
Metals have high boiling and melting point where as non-metals have low boiling and melting point. Metals form oxides that are basic while non-metal form oxides that are acidic. Metals are solid at room temperature while non-metal are solids, liquids or gases at room temperature.
Wednesday, September 8, 2010
Investigating mixtures and compounds
My friends and I did some experiments to investigate the properties of a mixture and a compound. The experiment needs tripod stand, evaporating dish, glass rod, wire gauze, Bunsen burner, sulfur powder, iron filings, filter paper and a magnet wrapped in a small piece of paper.
Both sulfur and iron are elements. When they are mixed, a mixture of iron and sulfur is formed and when they are heated together, a compound, iron sulfide is formed.
Observing Elements
1. Place the sulfur powder on a piece of filter paper. The sulfur is in a form of yellow powder.
2. Wrap on end of the magnet with a small piece of paper the move the magnet close to the sulfur powder. The sulfur powder is not being attracted by the magnet.
3. Place the iron filings in an evaporating dish. The iron filings are in a form of black powder.
4. Move the magnet close to the iron filings. The iron filings are being attracted to the magnet.
Observing a mixture
5. Pour the sulfur powder into the evaporating dish of iron filings. Mix it thoroughly with the iron filings using a glass rod. The mixture is a mixture of yellow and black powder.
6. Move the magnet close to the mixture. Only the iron filings are being attracted to the magnet.
Observing a compound
7. Heat the evaporating dish over the Bunsen flame until no more change occurs. Allow the evaporating dish to cool. The compound is in a form of a dark grey powder.
8. Move the magnet close to the compound. The compound is not attracted to the magnet.
I think that the mixture of iron and sulfur has the properties of iron and sulfur because no heat is released or taken in and the basic appearances of black and yellow powder are still evident.
Heat is needed for a compound to form.
I think that the compound formed from iron and sulfur does not have the properties of iron and sulfur because the colour is entirely different from its constituent components and no parts of the compound is attracted to the magnet.
Hence, I can conclude that heat is not needed to form a mixture but heat is needed to form a compound. A mixture has the properties of its constituent elements while a compound does not have the properties of its constituent elements. A mixture can be separated into its elements by physical methods but a compound cannot be separated into its elements by physical methods.
Both sulfur and iron are elements. When they are mixed, a mixture of iron and sulfur is formed and when they are heated together, a compound, iron sulfide is formed.
Observing Elements
1. Place the sulfur powder on a piece of filter paper. The sulfur is in a form of yellow powder.
2. Wrap on end of the magnet with a small piece of paper the move the magnet close to the sulfur powder. The sulfur powder is not being attracted by the magnet.
3. Place the iron filings in an evaporating dish. The iron filings are in a form of black powder.
4. Move the magnet close to the iron filings. The iron filings are being attracted to the magnet.
Observing a mixture
5. Pour the sulfur powder into the evaporating dish of iron filings. Mix it thoroughly with the iron filings using a glass rod. The mixture is a mixture of yellow and black powder.
6. Move the magnet close to the mixture. Only the iron filings are being attracted to the magnet.
Observing a compound
7. Heat the evaporating dish over the Bunsen flame until no more change occurs. Allow the evaporating dish to cool. The compound is in a form of a dark grey powder.
8. Move the magnet close to the compound. The compound is not attracted to the magnet.
I think that the mixture of iron and sulfur has the properties of iron and sulfur because no heat is released or taken in and the basic appearances of black and yellow powder are still evident.
Heat is needed for a compound to form.
I think that the compound formed from iron and sulfur does not have the properties of iron and sulfur because the colour is entirely different from its constituent components and no parts of the compound is attracted to the magnet.
Hence, I can conclude that heat is not needed to form a mixture but heat is needed to form a compound. A mixture has the properties of its constituent elements while a compound does not have the properties of its constituent elements. A mixture can be separated into its elements by physical methods but a compound cannot be separated into its elements by physical methods.
Testing for the presence of starch
My friends and I did an experiment to test if there are starch on a variegated leaf. The experiment needs boiling water, beaker, ethanol, boiling tube, glass rod, white tile and iodine solution.
1. Place the leaf in the dark for sometime so the leaf will not photosynthesize
2. Take the leaf and put in the beaker and fill the beaker with boiling water
3. Leave the leaf in boiling water for a while to kill it
4. Take the leaf out and put it in the boiling tube then fill it with ethanol
5. Use the glass rod and stir the ethanol until the leaf changes colour (the use of the ethanol is to remove the chlorophyll in the leaf)
6. Take the leaf out and then rinse it in water
7. Place the leaf on the white tile and drop some iodine solution on the leaf
After a while, the iodine solution on the green pigment of the leaf turned blue black while the iodine solution on the non green part of the leaf remained yellowish brown. Hence, I can conclude that chlorophyll is needed for photosynthesis as there is no chlorophyll in the non green part of the variegated leaf.
1. Place the leaf in the dark for sometime so the leaf will not photosynthesize
2. Take the leaf and put in the beaker and fill the beaker with boiling water
3. Leave the leaf in boiling water for a while to kill it
4. Take the leaf out and put it in the boiling tube then fill it with ethanol
5. Use the glass rod and stir the ethanol until the leaf changes colour (the use of the ethanol is to remove the chlorophyll in the leaf)
6. Take the leaf out and then rinse it in water
7. Place the leaf on the white tile and drop some iodine solution on the leaf
After a while, the iodine solution on the green pigment of the leaf turned blue black while the iodine solution on the non green part of the leaf remained yellowish brown. Hence, I can conclude that chlorophyll is needed for photosynthesis as there is no chlorophyll in the non green part of the variegated leaf.
Sunday, September 5, 2010
Newton's laws of motion
Newton's laws of motion are three physical laws that form the basis for classical mechanics. They describe the relationship between the forces acting on a body and its motion due to those forces. They have been expressed in several different ways over nearly three centuries, and can be summarised as follows:
1. First Law: Every body remains in a state of rest or uniform motion (constant velocity) unless it is acted upon by an external unbalanced force. This means that in the absence of a non-zero net force, the center of mass of a body either remains at rest, or moves at a constant speed in a straight line.
2. Second Law: A body of mass m subject to a force F undergoes an acceleration a that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass, i.e., F = ma. Alternatively, the total force applied on a body is equal to the time derivative of linear momentum of the body.
3. Third Law: The mutual forces of action and reaction between two bodies are equal, opposite and collinear. This means that whenever a first body exerts a force F on a second body, the second body exerts a force −F on the first body. F and −F are equal in magnitude and opposite in direction. This law is sometimes referred to as the action-reaction law, with F called the "action" and −F the "reaction".
The laws of motion were first compiled by Sir Isaac Newton in his work Philosophiæ Naturalis Principia Mathematica, first published on July 5, 1687. Newton used them to explain and investigate the motion of many physical objects and systems. For example, in the third volume of the text, Newton showed that these laws of motion, combined with his law of universal gravitation, explained Kepler's laws of planetary motion.
Newton's laws are applied to bodies (objects) which are considered or idealized as a particle, in the sense that the extent of the body is neglected in the evaluation of its motion, i.e., the object is small compared to the distances involved in the analysis, or the deformation and rotation of the body is of no importance in the analysis. Therefore, a planet can be idealized as a particle for analysis of its orbital motion around a star.
The first law states that if the resultant force (the vector sum of all forces acting on an object) is zero, then the velocity of the object is constant. Consequently:
• An object that is at rest will stay at rest unless an unbalanced force acts upon it.
• An object that is in motion will not change its velocity unless an unbalanced force acts upon it.
Newton's laws are valid only in an inertial reference frame. Any reference frame that is in uniform motion with respect to an inertial frame is also an inertial frame, i.e. Galilean invariance or the principle of Newtonian relativity.
Newton's first law is a restatement of the law of inertia which Galileo had already described and Newton gave credit to Galileo. Aristotle had the view that all objects have a natural place in the universe: that heavy objects like rocks wanted to be at rest on the Earth and that light objects like smoke wanted to be at rest in the sky and the stars wanted to remain in the heavens. He thought that a body was in its natural state when it was at rest, and for the body to move in a straight line at a constant speed an external agent was needed to continually propel it, otherwise it would stop moving. Galileo, however, realized that a force is necessary to change the velocity of a body, i.e., acceleration, but no force is needed to maintain its velocity. This insight leads to Newton's First Law —no force means no acceleration, and hence the body will maintain its velocity.
The second law states that F=ma. Thus, the net force applied to a body produces a proportional acceleration. Any mass that is gained or lost by the system will cause a change in momentum that is not the result of an external force. A different equation is necessary for variable-mass systems. Consistent with the first law, the time derivative of the momentum is non-zero when the momentum changes direction, even if there is no change in its magnitude; such is the case with uniform circular motion. The relationship also implies the conservation of momentum: when the net force on the body is zero, the momentum of the body is constant. Any net force is equal to the rate of change of the momentum. Newton's second law requires modification if the effects of special relativity are to be taken into account, because at high speeds the approximation that momentum is the product of rest mass and velocity is not accurate.
The Third Law means that all forces are interactions between different bodies, and thus that there is no such thing as a unidirectional force or a force that acts on only one body. If body A exerts a force on body B, body B simultaneously exerts a force of the same magnitude on body A— both forces acting along the same line. An example is two skaters, the skaters' forces on each other are equal in magnitude, but act in opposite directions. Although the forces are equal, the accelerations are not: the less massive skater will have a greater acceleration due to Newton's second law. The two forces in Newton's third law are of the same type (e.g., if the road exerts a forward frictional force on an accelerating car's tires, then it is also a frictional force that Newton's third law predicts for the tires pushing backward on the road).
Newton used the third law to derive the law of conservation of momentum; however from a deeper perspective, conservation of momentum is the more fundamental idea (derived via Noether's theorem from Galilean invariance), and holds in cases where Newton's third law appears to fail, for instance when force fields as well as particles carry momentum, and in quantum mechanics.
In my opinion, I feel that Newton is very capable as he was the first to discover the laws of motion. These laws are very beneficial to us as it would enable us to understand things we have observed in greater depth and it serves as a stepping stone to scientists who would like to find out more about the motion of an object in detailed.
1. First Law: Every body remains in a state of rest or uniform motion (constant velocity) unless it is acted upon by an external unbalanced force. This means that in the absence of a non-zero net force, the center of mass of a body either remains at rest, or moves at a constant speed in a straight line.
2. Second Law: A body of mass m subject to a force F undergoes an acceleration a that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass, i.e., F = ma. Alternatively, the total force applied on a body is equal to the time derivative of linear momentum of the body.
3. Third Law: The mutual forces of action and reaction between two bodies are equal, opposite and collinear. This means that whenever a first body exerts a force F on a second body, the second body exerts a force −F on the first body. F and −F are equal in magnitude and opposite in direction. This law is sometimes referred to as the action-reaction law, with F called the "action" and −F the "reaction".
The laws of motion were first compiled by Sir Isaac Newton in his work Philosophiæ Naturalis Principia Mathematica, first published on July 5, 1687. Newton used them to explain and investigate the motion of many physical objects and systems. For example, in the third volume of the text, Newton showed that these laws of motion, combined with his law of universal gravitation, explained Kepler's laws of planetary motion.
Newton's laws are applied to bodies (objects) which are considered or idealized as a particle, in the sense that the extent of the body is neglected in the evaluation of its motion, i.e., the object is small compared to the distances involved in the analysis, or the deformation and rotation of the body is of no importance in the analysis. Therefore, a planet can be idealized as a particle for analysis of its orbital motion around a star.
The first law states that if the resultant force (the vector sum of all forces acting on an object) is zero, then the velocity of the object is constant. Consequently:
• An object that is at rest will stay at rest unless an unbalanced force acts upon it.
• An object that is in motion will not change its velocity unless an unbalanced force acts upon it.
Newton's laws are valid only in an inertial reference frame. Any reference frame that is in uniform motion with respect to an inertial frame is also an inertial frame, i.e. Galilean invariance or the principle of Newtonian relativity.
Newton's first law is a restatement of the law of inertia which Galileo had already described and Newton gave credit to Galileo. Aristotle had the view that all objects have a natural place in the universe: that heavy objects like rocks wanted to be at rest on the Earth and that light objects like smoke wanted to be at rest in the sky and the stars wanted to remain in the heavens. He thought that a body was in its natural state when it was at rest, and for the body to move in a straight line at a constant speed an external agent was needed to continually propel it, otherwise it would stop moving. Galileo, however, realized that a force is necessary to change the velocity of a body, i.e., acceleration, but no force is needed to maintain its velocity. This insight leads to Newton's First Law —no force means no acceleration, and hence the body will maintain its velocity.
The second law states that F=ma. Thus, the net force applied to a body produces a proportional acceleration. Any mass that is gained or lost by the system will cause a change in momentum that is not the result of an external force. A different equation is necessary for variable-mass systems. Consistent with the first law, the time derivative of the momentum is non-zero when the momentum changes direction, even if there is no change in its magnitude; such is the case with uniform circular motion. The relationship also implies the conservation of momentum: when the net force on the body is zero, the momentum of the body is constant. Any net force is equal to the rate of change of the momentum. Newton's second law requires modification if the effects of special relativity are to be taken into account, because at high speeds the approximation that momentum is the product of rest mass and velocity is not accurate.
The Third Law means that all forces are interactions between different bodies, and thus that there is no such thing as a unidirectional force or a force that acts on only one body. If body A exerts a force on body B, body B simultaneously exerts a force of the same magnitude on body A— both forces acting along the same line. An example is two skaters, the skaters' forces on each other are equal in magnitude, but act in opposite directions. Although the forces are equal, the accelerations are not: the less massive skater will have a greater acceleration due to Newton's second law. The two forces in Newton's third law are of the same type (e.g., if the road exerts a forward frictional force on an accelerating car's tires, then it is also a frictional force that Newton's third law predicts for the tires pushing backward on the road).
Newton used the third law to derive the law of conservation of momentum; however from a deeper perspective, conservation of momentum is the more fundamental idea (derived via Noether's theorem from Galilean invariance), and holds in cases where Newton's third law appears to fail, for instance when force fields as well as particles carry momentum, and in quantum mechanics.
In my opinion, I feel that Newton is very capable as he was the first to discover the laws of motion. These laws are very beneficial to us as it would enable us to understand things we have observed in greater depth and it serves as a stepping stone to scientists who would like to find out more about the motion of an object in detailed.
Friday, September 3, 2010
Maglev
Maglev, or magnetic levitation, is a system of transportation that suspends, guides and propels vehicles, predominantly trains, using magnetic levitation from a very large number of magnets for lift and propulsion. This method has the potential to be faster, quieter and smoother than wheeled mass transit systems. The power needed for levitation is usually not a particularly large percentage of the overall consumption; most of the power used is needed to overcome air drag, as with any other high speed train.
The highest recorded speed of a Maglev train is 581 kilometres per hour (361 mph), achieved in Japan in 2003, 6 kilometres per hour (3.7 mph) faster than the conventional TGV speed record.
The first commercial Maglev "people-mover" was officially opened in 1984 in Birmingham, England. It operated on an elevated 600-metre (2,000 ft) section of monorail track between Birmingham International Airport and Birmingham International railway station, running at speeds up to 42 km/h (26 mph); the system was eventually closed in 1995 due to reliability and design problems.
Perhaps the most well known implementation of high-speed maglev technology currently operating commercially is the IOS (initial operating segment) demonstration line of the German-built Transrapid train in Shanghai, China that transports people 30 km (18.6 miles) to the airport in just 7 minutes 20 seconds, achieving a top speed of 431 km/h (268 mph), averaging 250 km/h (160 mph).
First patents
High speed transportation patents were granted to various inventors throughout the world. Early United States patents for a linear motor propelled train were awarded to the inventor, Alfred Zehden (German). The inventor was awarded U.S. Patent 782,312 (June 21, 1902) and U.S. Patent RE12,700 (August 21, 1907). In 1907, another early electromagnetic transportation system was developed by F. S. Smith. A series of German patents for magnetic levitation trains propelled by linear motors were awarded to Hermann Kemper between 1937 and 1941. An early modern type of maglev train was described in U.S. Patent 3,158,765, Magnetic system of transportation, by G. R. Polgreen (August 25, 1959). The first use of "maglev" in a United States patent was in "Magnetic levitation guidance" by Canadian Patents and Development Limited
Technology Overview
The term "maglev" refers not only to the vehicles, but to the railway system as well, specifically designed for magnetic levitation and propulsion. All operational implementations of maglev technology have had minimal overlap with wheeled train technology and have not been compatible with conventional rail tracks. Because they cannot share existing infrastructure, these maglev systems must be designed as complete transportation systems. The Applied Levitation SPM Maglev system is inter-operable with steel rail tracks and would permit maglev vehicles and conventional trains to operate at the same time on the same right of way. MAN in Germany also designed a maglev system that worked with conventional rails, but it was never fully developed.
There are two particularly notable types of maglev technology:
• For electromagnetic suspension (EMS), electromagnets in the train attract it to a magnetically conductive (usually steel) track.
• Electrodynamic suspension (EDS) uses electromagnets on both track and train to push the train away from the rail.
Another experimental technology, which was designed, proven mathematically, peer reviewed, and patented, but is yet to be built, is the magnetodynamic suspension (MDS), which uses the attractive magnetic force of a permanent magnet array near a steel track to lift the train and hold it in place. Other technologies such as repulsive permanent magnets and superconducting magnets have seen some research.
Advantages and disadvantages
Compared to conventional trains
Major comparative differences between the two technologies lie in backward-compatibility, rolling resistance, weight, noise, design constraints, and control systems.
• Backwards Compatibility: Maglev trains currently in operation are not compatible with conventional track, and therefore require all new infrastructure for their entire route. By contrast conventional high speed trains such as the TGV are able to run at reduced speeds on existing rail infrastructure, thus reducing expenditure where new infrastructure would be particularly expensive (such as the final approaches to city terminals), or on extensions where traffic does not justify new infrastructure.
• Efficiency: Due to the lack of physical contact between the track and the vehicle, maglev trains experience no rolling resistance, leaving only air resistance and electromagnetic drag, potentially improving power efficiency.
• Weight: The weight of the large electromagnets in many EMS and EDS designs is a major design issue. A very strong magnetic field is required to levitate a massive train. For this reason one research path is using superconductors to improve the efficiency of the electromagnets, and the energy cost of maintaining the field.
• Noise: Because the major source of noise of a maglev train comes from displaced air, maglev trains produce less noise than a conventional train at equivalent speeds. However, the psychoacoustic profile of the maglev may reduce this benefit: a study concluded that maglev noise should be rated like road traffic while conventional trains have a 5-10 dB "bonus" as they are found less annoying at the same loudness level.
• Design Comparisons: Braking and overhead wire wear have caused problems for the Fastech 360 railed Shinkansen. Maglev would eliminate these issues. Magnet reliability at higher temperatures is a countervailing comparative disadvantage (see suspension types), but new alloys and manufacturing techniques have resulted in magnets that maintain their levitational force at higher temperatures.
As with many technologies, advances in linear motor design have addressed the limitations noted in early maglev systems. As linear motors must fit within or straddle their track over the full length of the train, track design for some EDS and EMS maglev systems is challenging for anything other than point-to-point services. Curves must be gentle, while switches are very long and need care to avoid breaks in current. An SPM maglev system, in which the vehicle is permanently levitated over the tracks, can instantaneously switch tracks using electronic controls, with no moving parts in the track. A prototype SPM maglev train has also navigated curves with radius equal to the length of the train itself, which indicates that a full-scale train should be able to navigate curves with the same or narrower radius as a conventional train.
• Control Systems: EMS Maglev needs very fast-responding control systems to maintain a stable height above the track; this needs careful design in the event of a failure in order to avoid crashing into the track during a power fluctuation. Other maglev systems do not necessarily have this problem. For example, SPM maglev systems have a stable levitation gap of several centimeters.
A Maglev train has it advantages and disadvantages. Hence you cannot say which train, whether the Maglev train or the conventional train is the best but I think that it should depend on the person riding it whether which train is more suitable for himself.
The highest recorded speed of a Maglev train is 581 kilometres per hour (361 mph), achieved in Japan in 2003, 6 kilometres per hour (3.7 mph) faster than the conventional TGV speed record.
The first commercial Maglev "people-mover" was officially opened in 1984 in Birmingham, England. It operated on an elevated 600-metre (2,000 ft) section of monorail track between Birmingham International Airport and Birmingham International railway station, running at speeds up to 42 km/h (26 mph); the system was eventually closed in 1995 due to reliability and design problems.
Perhaps the most well known implementation of high-speed maglev technology currently operating commercially is the IOS (initial operating segment) demonstration line of the German-built Transrapid train in Shanghai, China that transports people 30 km (18.6 miles) to the airport in just 7 minutes 20 seconds, achieving a top speed of 431 km/h (268 mph), averaging 250 km/h (160 mph).
First patents
High speed transportation patents were granted to various inventors throughout the world. Early United States patents for a linear motor propelled train were awarded to the inventor, Alfred Zehden (German). The inventor was awarded U.S. Patent 782,312 (June 21, 1902) and U.S. Patent RE12,700 (August 21, 1907). In 1907, another early electromagnetic transportation system was developed by F. S. Smith. A series of German patents for magnetic levitation trains propelled by linear motors were awarded to Hermann Kemper between 1937 and 1941. An early modern type of maglev train was described in U.S. Patent 3,158,765, Magnetic system of transportation, by G. R. Polgreen (August 25, 1959). The first use of "maglev" in a United States patent was in "Magnetic levitation guidance" by Canadian Patents and Development Limited
Technology Overview
The term "maglev" refers not only to the vehicles, but to the railway system as well, specifically designed for magnetic levitation and propulsion. All operational implementations of maglev technology have had minimal overlap with wheeled train technology and have not been compatible with conventional rail tracks. Because they cannot share existing infrastructure, these maglev systems must be designed as complete transportation systems. The Applied Levitation SPM Maglev system is inter-operable with steel rail tracks and would permit maglev vehicles and conventional trains to operate at the same time on the same right of way. MAN in Germany also designed a maglev system that worked with conventional rails, but it was never fully developed.
There are two particularly notable types of maglev technology:
• For electromagnetic suspension (EMS), electromagnets in the train attract it to a magnetically conductive (usually steel) track.
• Electrodynamic suspension (EDS) uses electromagnets on both track and train to push the train away from the rail.
Another experimental technology, which was designed, proven mathematically, peer reviewed, and patented, but is yet to be built, is the magnetodynamic suspension (MDS), which uses the attractive magnetic force of a permanent magnet array near a steel track to lift the train and hold it in place. Other technologies such as repulsive permanent magnets and superconducting magnets have seen some research.
Advantages and disadvantages
Compared to conventional trains
Major comparative differences between the two technologies lie in backward-compatibility, rolling resistance, weight, noise, design constraints, and control systems.
• Backwards Compatibility: Maglev trains currently in operation are not compatible with conventional track, and therefore require all new infrastructure for their entire route. By contrast conventional high speed trains such as the TGV are able to run at reduced speeds on existing rail infrastructure, thus reducing expenditure where new infrastructure would be particularly expensive (such as the final approaches to city terminals), or on extensions where traffic does not justify new infrastructure.
• Efficiency: Due to the lack of physical contact between the track and the vehicle, maglev trains experience no rolling resistance, leaving only air resistance and electromagnetic drag, potentially improving power efficiency.
• Weight: The weight of the large electromagnets in many EMS and EDS designs is a major design issue. A very strong magnetic field is required to levitate a massive train. For this reason one research path is using superconductors to improve the efficiency of the electromagnets, and the energy cost of maintaining the field.
• Noise: Because the major source of noise of a maglev train comes from displaced air, maglev trains produce less noise than a conventional train at equivalent speeds. However, the psychoacoustic profile of the maglev may reduce this benefit: a study concluded that maglev noise should be rated like road traffic while conventional trains have a 5-10 dB "bonus" as they are found less annoying at the same loudness level.
• Design Comparisons: Braking and overhead wire wear have caused problems for the Fastech 360 railed Shinkansen. Maglev would eliminate these issues. Magnet reliability at higher temperatures is a countervailing comparative disadvantage (see suspension types), but new alloys and manufacturing techniques have resulted in magnets that maintain their levitational force at higher temperatures.
As with many technologies, advances in linear motor design have addressed the limitations noted in early maglev systems. As linear motors must fit within or straddle their track over the full length of the train, track design for some EDS and EMS maglev systems is challenging for anything other than point-to-point services. Curves must be gentle, while switches are very long and need care to avoid breaks in current. An SPM maglev system, in which the vehicle is permanently levitated over the tracks, can instantaneously switch tracks using electronic controls, with no moving parts in the track. A prototype SPM maglev train has also navigated curves with radius equal to the length of the train itself, which indicates that a full-scale train should be able to navigate curves with the same or narrower radius as a conventional train.
• Control Systems: EMS Maglev needs very fast-responding control systems to maintain a stable height above the track; this needs careful design in the event of a failure in order to avoid crashing into the track during a power fluctuation. Other maglev systems do not necessarily have this problem. For example, SPM maglev systems have a stable levitation gap of several centimeters.
A Maglev train has it advantages and disadvantages. Hence you cannot say which train, whether the Maglev train or the conventional train is the best but I think that it should depend on the person riding it whether which train is more suitable for himself.
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