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General information about materials, their structure and properties
General information about materials.
All chemically based materials are divided into two main groups - metallic and non-metallic.
Metals include metals and their alloys. Metals make up more than 2/3 of all known chemical elements. Metal materials are divided into black and non-ferrous. The black ones include iron and alloys based on it - steels and cast irons. All other metals are non-ferrous. Pure metals have poor mechanical properties compared to alloys, and therefore their use is limited to those cases where it is necessary to use their special properties.
Non-metallic materials include various plastics (layered, fibrous, powder, gas-filled), rubber materials, wood materials(lumber, wood veneer), textile materials, inorganic (ceramics, glass) and composite materials.
Practical value various materials not the same. Ferrous metals have gained the greatest use in engineering. More than 90% of all metal products are made on the basis of iron. However, non-ferrous metals have a number of valuable physical and chemical properties that make them indispensable. Non-metallic materials also occupy a place in industry, but their use is small (about 10%), and the thirty-year-old prediction that non-metallic materials would significantly replace metal ones by the end of the century did not come true. In other areas, the use of various metal materials is currently developing at a faster pace than metal materials.
The structure of materials.
All solids are divided into amorphous and crystalline.
In amorphous bodies, atoms are arranged randomly, i.e. in disorder, without any system, therefore, when heated, bodies soften in a large temperature range, become viscous, and then turn into a liquid state. On cooling, the process goes in the opposite direction. Examples of amorphous bodies are glass, glue, wax, rosin, i.e. amorphous structure is inherent mainly in non-metals.
In crystalline bodies, atoms are arranged in a strictly defined sequence. The bodies remain solid, i.e. retain the shape given to them until a certain temperature, at which they pass into a liquid state. On cooling, the process goes in the opposite direction. The transition from one state to another occurs at a certain melting point. Solids with a crystalline structure include table salt, quartz, granulated sugar, metals and alloys.
Atomic-crystal structure - the mutual arrangement of atoms in a crystal. A crystal consists of atoms (ions) arranged in a certain order, which is periodically repeated in three dimensions. The smallest complex of atoms, which, when repeated in space, allows you to reproduce a spatial crystal lattice, is called an elementary cell. For simplification, it is customary to replace the spatial image with diagrams, where the centers of gravity of the particles are represented by dots. At the points of intersection of straight lines are atoms; they are called lattice nodes. The distances between the centers of atoms located in neighboring lattice sites are called parameters, or lattice periods.
An ideal crystal lattice is a multiple repetition of elementary crystal cells. A real metal is characterized by the presence of a large number of structural defects that violate the periodicity of the arrangement of atoms in the crystal lattice.
There are three types of defects in the crystal structure: point, linear and surface. Point defects are characterized by small sizes, their size does not exceed several atomic diameters. Point defects include: a) free places in the nodes of the crystal lattice - vacancies (Schottky defects); b) atoms that have shifted from the nodes of the crystal lattice into interstitial spaces - dislocated atoms (Frenkel defects); c) atoms of other elements located both in the nodes and in the interstices of the crystal lattice - impurity atoms. Linear defects are characterized by small sizes in two dimensions, but have a significant extent in the third dimension. The most important type of linear defects is dislocations (lat. dislocation - displacement). Surface defects have a small thickness and significant dimensions in the other two dimensions. Usually these are the junctions of two oriented sections of the crystal lattice. They can be grain boundaries, fragment boundaries within a grain, block boundaries within fragments.
The properties of materials directly depend on the structure and defects.
Material properties.
Physical properties determine the behavior of materials in thermal, gravitational, electromagnetic and radiation fields. Of the important physical properties, thermal conductivity, density, linear expansion coefficient can be distinguished.
Density is the ratio of the mass of a homogeneous material to a unit of its volume. This property is important when using materials in aviation and rocket technology, where created structures should be light and strong.
The melting point is the temperature at which a metal changes from a solid state to a liquid state. The lower the melting temperature of the metal, the easier the processes of its melting, welding, and the cheaper they are.
Electrical conductivity is the ability of a material to conduct an electric current well and without heat loss. Metals and their alloys, especially copper and aluminum, have good electrical conductivity. Most non-metallic materials are not capable of conducting electricity, which is also important property used in electrical insulating materials.
Thermal conductivity is the ability of a material to transfer heat from more heated parts of bodies to less heated ones. Metallic materials are characterized by good thermal conductivity.
Magnetic properties i.e. only iron, nickel, cobalt and their alloys have the ability to be well magnetized.
The coefficients of linear and volumetric expansion characterize the ability of a material to expand when heated.
Chemical properties characterize the propensity of materials to interact with various substances and are related to the ability of materials to withstand the harmful effects of these substances. The ability of metals and alloys to resist the action of various aggressive media is called corrosion resistance, and the similar ability of non-metallic materials is called chemical resistance.
Mechanical properties characterize the ability of materials to resist the action of external forces. The main mechanical properties include strength, hardness, impact strength, elasticity, ductility, brittleness, etc.
Strength is the ability of a material to resist the damaging effects of external forces.
Hardness is the ability of a material to resist the intrusion of another, more rigid body into it under the action of a load.
Viscosity is the property of a material to resist fracture under dynamic loads.
Elasticity is the property of materials to restore their size and shape after the termination of the load.
Plasticity is the ability of materials to change their size and shape under the action of external forces without breaking down.
Brittleness is the property of materials to collapse under the influence of external forces without residual deformations.
Technological properties determine the ability of materials to undergo various types of processing. Casting properties are characterized by the ability of metals and alloys in the molten state to fill the mold cavity well and accurately reproduce its shape (liquid flowability), the amount of volume reduction during solidification (shrinkage), the tendency to form cracks and pores, and the tendency to absorb gases in the molten state.
Operational (service) properties include heat resistance, heat resistance, wear resistance, radiation resistance, corrosion and chemical resistance, etc.
Heat resistance characterizes the ability of a metal material to resist oxidation in a gaseous environment at high temperature.
Heat resistance characterizes the ability of a material to maintain mechanical properties at high temperatures.
Wear resistance is the ability of a material to resist the destruction of its surface layers during friction.
Radiation resistance characterizes the ability of a material to resist the action of nuclear radiation.
Question 2: Classification of textile fibers.
Textile fiber is an extended body, flexible and strong, with small transverse dimensions, limited length, suitable for the manufacture of yarn and textile materials.
The classification of fibers is based on their chemical composition and origin.
Depending on the origin, textile fibers are divided into natural and chemical.
Natural fibers include fibers of plant, animal and natural origin, which are formed in nature without the direct participation of man. Natural plant fibers are made up of cellulose; they are obtained from the surface of seeds (cotton), fruits (coir), from stems (flax, ramie, hemp, jute, etc.) and plant leaves (abaca, sisal). Natural fibers of animal origin are composed of proteins - keratin (the wool of various animals), or fibroin (mulberry or oak silkworm silk).
Chemical fibers include fibers created in the factory by molding from organic natural or synthetic polymers or inorganic substances. According to their composition, chemical fibers are divided into artificial and synthetic.
Artificial fibers are obtained from high-molecular compounds found in finished form (cellulose, proteins). They are obtained by chemical processing of natural polymers of plant and animal origin, from the waste of pulp production and the food industry.
A polymer is a substance whose molecules consist of a large number of repeating units. The raw materials for polymers are wood, seeds, milk, etc. Textile materials based on artificial cellulose fibers, such as viscose, polynose, copper-ammonia, triacetate, acetate, have the greatest application in the clothing industry.
Synthetic fibers are obtained by chemical synthesis of polymers, i.e. creating substances with a complex molecular structure from simpler ones, most often from products of oil and coal processing. These are polyamide, polyether, polyurethane fibers, as well as polyacrylonitrile (PAN), polyvinyl chloride (PVC), polyvinyl alcohol, polyolefin. Also, according to the composition, synthetic fibers are divided into carbochain and heterochain. Heterochain fibers are formed from polymers, in the main molecular chain of which, in addition to carbon atoms, there are atoms of other elements. Fibers are called carbon chain fibers, which are obtained from polymers that have only carbon atoms in the main chain of macromolecules.
material property structure defect
Used Books
1. Solntsev Yu.P. Materials Science. Application and selection of materials: Tutorial/ Solntsev Yu.P., Borzenko E.I., Vologzhanina S.A. - St. Petersburg: KHIMIZDAT, 2007. - 200 p.
2. Buzov B.A. Material science in the production of light industry products (clothing): Textbook for students. higher textbook institutions / B.A. Buzov, N.D. Adymenkova: Ed. B.A. Buzova. - M.: Publishing center "Academy", 2004 - 448 p.
3. Savostitsky N.A. Materials science of garment production: a textbook for students. medium institutions. prof. education / N.A. Savostitsky, E.K. Amirov. - 7th ed., Sr. - M.: Publishing center "Academy", 2013. - 272 p.
4. Metals and alloys. Reference book / V. K. Afonin and others - NPO "Professional" St. Petersburg, 2003 - 200 p.
5. Solntsev Yu.P. "Materials Science" / Yu.P. Solntsev, E.I. Pryakhin - St. Petersburg: Himizdat, 2007, 783 pp.
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Development of a sketch of a model of a wedding dress. Determination of the structure, structure, geometric mechanical and physical properties of tissue. The choice and characteristics of the main, lining, cushioning, fastening, finishing materials and accessories for the product.
At technology lessons, children learn to process not only fabric, paper and cardboard, but also various parts of plants, minerals, artificial materials and waste materials - waste of consumer goods, etc. Children collect them on excursions, bring them in the form of semi-finished products and blanks or ready-made industrial products.
Natural materials include plant branches, leaves, flowers, seeds, roots, bark, moss, fruits, river and sea stones, sand, clay, as well as parts of animals - fish bones, shells and shells of mollusks, dried insects, poultry egg shells, feathers. In the form of semi-finished products in the classroom, boards of various sizes are used.
From artificial materials for work, students often use plasticine, plastic, plywood, fiberboard, soft sheet metals, pieces of plastic, ceramics.
Finished industrial products include such waste materials as packaging, boxes, ribbons for decorating gifts and bouquets, jars, bottles, accessories for decorating clothes and premises.
Processing of the listed materials is impossible without special knowledge of materials science and technology of their processing. Children acquire such knowledge in the process of observations and experiments.
In the first grade, the following observations should be made: determining the shape and color of leaves, acorns, nutshells, comparing the properties of sand and clay, wood and metal, identifying artistic expressive features in a folk toy, etc.
In the second class, observations of the properties of cones, bark, branches are carried out. Features of processing soft and hard materials are revealed.
In the third grade, students observe the properties of dried plants, straw, identify the properties of ceramics, plastics, glass. Students learn to choose best ways processing of these materials.
In the fourth grade, work is underway to generalize and deepen existing knowledge. Students independently choose the best ways to process materials, develop the simplest technological maps for creative projects.
The teacher provides thorough instruction on the collection, storage and pre-processing of various materials. Particular attention is paid to hygiene requirements, as well as safety rules for the collection, transportation and storage of materials. In addition, the teacher is obliged to point out that in our country there is a law on environmental protection, which obliges us to take care of natural resources. It is not recommended to use finished products that have undergone special processing and are suitable for human consumption (cereals, pasta, flour, legumes). For work, use only products with an expired shelf life.
To work with different materials, special tools are selected.
Marking and measuring tools.
The pencils– for marking details on wood, hard pencils of grade 2 are required T and 3 T. The sharpening angle of the pencil should be sharp. When marking, the pencil must be held at a slight inclination in the direction of its movement and pressed firmly against the edge of the template or ruler;
Rulers- For measurement, they usually use a metal ruler or tape measure. For marking on wood, it is more convenient to use a thick wooden ruler or a carpenter's square. The marking of round parts is carried out with a joiner's compass. The marking of straight lines on metal is carried out using a scriber, on wood - with a thickness gauge.
Cutting tools.
Scissors- in the processing process, clerical and rarely locksmith scissors are used more often.
Knives- for work, well-sharpened knives with a short blade (90-100mm) are used. For splitting wood, it is more convenient to use a mower - a knife with a shorter and thicker blade. In the process of cutting, the knife is held obliquely, guiding its movement with the index finger. Natural materials are cut on stands and lining boards.
Hacksaws and jigsaws– designed for sawing wood and metals. For convenience, the processed materials are clamped in a vice or clamp.
wire cutters- used for biting off wire, thin twigs.
Stichel- a narrow cutter, having a cross-sectional shape acute angle or arcs (angular and semicircular). The shtichel is used when finishing wood products (flat-embossed carving), linoleum (cliché for linocut).
Mounting tools.
A hammer- used to assemble products with nails. When working with a hammer, care must be taken that the student does not hit the fingers holding the nail.
Pliers and round nose pliers- used when working with wire. These tools are used to bend and twist the wire.
Awl- used for making holes in soft or easy-to-machine materials. Piercing is performed on stands or backing boards.
Gimlet– Designed for drilling holes in harder materials. Work with a gimlet is performed on stands or lining boards.
Glue brush- should be tough. The width of the brush is chosen according to the dimensions of the surface of the connecting part.
Connecting parts and materials.
Nails- Large nails are not used in labor lessons. More often they use Nos. 1, 2, 3, 4, which corresponds to the length of the nail in centimeters.
Pin- a rod for a fixed connection of parts. The pin is easy to make from a match, twig or strip of paper. A pin connects parts from acorns, cones, stucco materials.
Glue- to connect natural materials, PVA glue, casein or carpentry glue is used. It is better to glue floating models with casein glue, PVA glue, BF, Moment. Gluing parts requires great care. Glue is applied to a thin material or the glued part of the surface of a smaller part. Dry leaves are smeared with glue from the center of the sheet to the edges. Glue the smeared leaves carefully after they have absorbed some of the moisture. Glue is applied to narrow and deep surfaces using the tip of an awl dipped in glue.
The task of a technology teacher is not only to provide students with tools and all the necessary materials, but also to keep them in good condition. Knives and scissors must be properly sharpened, the tip of the awls and gimlets must not be broken, the jigsaw file must be well stretched and ring like a string when touched with a finger, the swivel joints of the scissors and the engraver must be in good order, the impact part of the hammer must be well fixed on the handle. At each lesson, the teacher is obliged to instruct students about the rules for safe work with tools and some materials.
processed materials.
Wood- most often used in the work of high school students. In the primary classes, pine, spruce, birch, linden wood, as well as three-layer plywood made from them, are used. Wood is sawn in the transverse direction with a hacksaw and a jigsaw. The ends of sawn wood are cleaned with files, sandpaper. coloring wooden crafts oil paint.
In elementary grades, students make pointers, ecker, labels for the class plot. Design specifications are required for the manufacture of such products. For example, boards for labels must correspond to the specified dimensions, their edges must be sanded; the pegs must correspond to the given dimensions in length, thickness, their surface must be processed with a file and sandpaper.
Straw- dried stems of cereal plants, more often use straw of wheat, rye, oats. Straw must be processed before work - remove nodes, sort internodes by length and thickness. For the manufacture of a straw strip, blanks are poured hot water for a day, then each straw is cut lengthwise and ironed with a hot iron on a wooden lining board. Depending on the temperature of the iron, the straw acquires different color shades. Applications are made from straw, it is used for inlaying wood products. Store the straw in a dry ventilated place.
egg shell- an excellent material for the manufacture of bulk and flat products. It is well stained with food coloring, parts from the shell are fixed on glue, plasticine. For the manufacture of bulk products it is necessary to remove the contents from the egg using a medical syringe. The egg is also filled with heated paraffin using a syringe. By decorating the egg with various decoration details, you can make figures of animals, birds, fish, etc. From dyed eggshell you can make a mosaic panel by first covering the surface to be filled with a layer of plasticine.
plant leaves- used in dried form. The leaves are harvested in autumn, sorted by size, color, shape. The leaves are dried under pressure, or thermally (ironed with an iron). Store the finished material in a dry place.
birch bark- a favorite material of folk craftsmen. Birch bark is harvested in spring or early summer, cleaned of adhering particles. For ease of processing, the birch bark is steamed into hot water, divided into layers, cut into the desired shapes. Dry the material in a cool dry place.
Metals and alloys- in the classroom they often use thin soft wire, soft tin, aluminum foil, copper, brass, zinc, tin, lead. Manual processing of metals in a cold state is called locksmith work. Such materials are easy to process with scissors, wire cutters, hammers, pliers and round nose pliers. The cut edges of the parts are processed with a file or sandpaper. The color of parts or products can be changed by holding it over the flame of an alcohol lamp or painting with paints and varnishes for metal.
Holes in thin tin are made with an awl, punches. On thin tin and foil, it is easy to make indentations with the help of stamps, ballpoint pen and master the simplest techniques of chasing. Thin sheet can be bent and twisted with a hammer, pliers, round nose pliers.
Wire can be shaped into rings, polygons, spirals, etc. Wire can be used to make flat contour shapes and three-dimensional products, as well as frames for soft toys. Thin wire can also be used as a connecting material.
Stucco materials- clay, plasticine, plastic, gypsum, salt dough. They are currently available in stores. Clay can be obtained and prepared to work with students.
Oily clay is suitable for modeling. Skinny clay contains a large amount of impurities and is suitable for work after a special treatment - elutriation. Clay is harvested in the summer, dried, crushed and sieved. The crushed clay is placed in a large vessel (tub, tank), filled with water and thoroughly mixed. Floating impurities are removed. Heavy impurities (pebbles, sand) settle to the bottom, and small clay particles remain in suspension. This liquid composition is poured into another container, leaving large impurities at the bottom. After a while, the clay settles to the bottom. Water is drained from the surface. This process is called elutriation.
Before starting work, the clay is poured with water, mixed. A well-cooked mass should not stick to your hands. A sausage 10 cm long and 1 cm thick is rolled up from the prepared clay and lifted at one end. If the sausage does not fall apart, then the clay is ready to go. To improve the quality of clay, you can add paper fiber and vegetable oil. They work with clay on a backing board. Cut clay with wire or fishing line. Products are molded by hand, finishing details are made with a stack or special stamps.
Details made of stucco materials are connected by lubrication, pressing or pins. Products made of stucco materials are painted with gouache mixed with PVA glue (1x1, 2x1), watercolors (honey), varnished, or glazed (a glossy glassy alloy fixed by firing, coated on the surface of the product). Dry products in muffle furnaces, on radiators or on a well-ventilated surface.
plastics- chemical products. In the primary classes, easily processed plastics are used - organic glass, foam rubber, foam plastic, linoleum, nylon, etc. Plastic blanks are processed by cutting, drilling, they can be painted, joined with glue, sewn together. Toys and souvenirs are made from foam rubber and polystyrene foam. Foam rubber can be used for stuffing soft toys.
Linoleum used to make appliqués or clichés. Cliches for linocuts are made using engravers. Paint (gouache, printing ink) is applied to the finished surface of the cliché with a roller, put Blank sheet paper and iron it with a smooth object. Get an impression called a print.
Waste materials- packing boxes, corks, reels, tubes of cream, toothpaste, synthetic nets used for packing vegetables, bouquets, empty rods, tubes, etc. Making useful things from waste materials teaches students to be thrifty, develops them Creative skills, fantasy, ingenuity.
Papier mache- the most accessible technique for manufacturing bulk products in primary grades. For work you will need: newsprint, paste, gouache. As a form for the manufacture of volumetric products, dishes, toys, home-made forms that are made from plasticine are suitable. Paste for work is made from starch or flour. Products are dried in well-ventilated and warm places. Uneven places on the forms are leveled with sandpaper. Products are painted with gouache paints mixed with PVA glue in the ratio: 2 parts of paint and 1 part of glue.
Features of the processing of various materials, the methodology for studying their properties are described in numerous methodological manuals, books on arts and crafts, magazines on design and needlework, in the books of V.A. Baradulina, A.M. Gukasova, N.M. Konysheva, V.P. Kuznetsova and others.
Test questions.
1. What materials are called natural?
2. What is the peculiarity of storing various materials?
3. What is the principle by which the selection of various materials for work with students is carried out primary school?
4. What connecting materials are used to assemble products from natural materials?
Assignments for independent work.
1. Find (in printed or electronic sources) and study material containing information about the properties of natural materials, methods of their preparation and storage, processing techniques.
2. Select literature that covers the technology of manufacturing products from various materials.
Tasks for laboratory work.
1. Analyze the content of the module: "Technology of processing of structural materials and mechanical engineering" in the program "Technology". Highlight the skills that the authors of the program recommend to form in primary school students in the process of processing various materials.
2. Develop a plan for conducting an experiment for students in grade 3 to observe the properties of one of the specific natural materials.
3. Develop a summary of the lesson aimed at learning how to process one of the artificial materials.
4. Make 1 sample of products from natural materials, artificial materials and waste materials to demonstrate them at technology lessons in primary grades.
5. Develop instruction cards to teach students how to assemble one of the products from various materials.
Works: All Selected To help the teacher Competition "Educational project" Academic year: All 2015 / 2016 2014 / 2015 2013 / 2014 2012 / 2013 2011 / 2012 2010 / 2011 2009 / 2010 2008 / 2009 2007 / 2008 2006 / 2007 2005 / 2006 Sorting: Alphabetically Newest
Study of the mechanical properties of spider silk
In the work, the author explores the properties of spider silk and answers the question: is the thread of the web really so strong that a tank can be hung on it? The paper presents arguments "for" and "against", the author investigates the mechanical properties and draws the appropriate conclusions.
The study of free mechanical oscillations on the example of mathematical and spring pendulums
The paper defines the factors that affect the period and frequency of free mechanical oscillations of mathematical and spring pendulums. The dependence of the damping coefficient and the logarithmic damping decrement on the type of substance during oscillations of mathematical and spring pendulums is studied. The use of the set experiments allows us to consider the issue of free mechanical vibrations more clearly.
The properties of images obtained with the help of a converging lens are studied in this work. It has been experimentally determined that, depending on the distance of the object to the lens, its image can be imaginary or real, direct or inverted, enlarged or reduced, located both on the same side of the lens as the object, and on the other side of the lens relative to the object.
Studying the properties of materials used in local construction
The paper compares the thermal conductivity of materials used in local construction. The conclusion is made about the most popular building material and its advantages. A review of typical dwellings of different times and peoples and the materials used for their construction is made.
Studying the physical properties of dishwashing detergents
The paper presents the results of a study of the density, viscosity, surface tension coefficient of dishwashing liquids from some manufacturers.
Illustrated dictionary of physics. 8th grade
Designed as a presentation, the dictionary consists of four sections: thermal, electrical, electromagnetic phenomena and changes in the aggregate states of matter and includes 58 concepts. The words are located in two catalogs: alphabetical and thematic, and combined into a single hypertext. The slides of the dictionary contain a definition, a brief description, an illustration, a calculation formula for the term, buttons for moving to directories. Some hyperlinked concepts can be explained in more detail by going to the corresponding slide.
Interactive presentation "Physicists" using Visual Basic for Applications (VBA)
The interactive presentation was developed using the BASIC visual programming language for Microsoft Office applications. It can be used both in physics lessons and at extracurricular activities.
Interactive electronic game "Test yourself"
Learning is a very important process. But in the course of learning, fatigue accumulates, since you have to memorize many formulas, definitions, symbols for various quantities, etc. The element of the game will help to solve the problem of fatigue when memorizing program material. In this paper, a game model is proposed to test students' knowledge. The principle of the game is described, a fundamental circuit diagram, a list of details is given, didactic materials are attached.
Information and illustrated problem book
The task book is dedicated to the integration of two subjects - physics and biology. It includes 10 tasks that can be used in physics lessons on the topic "Mechanical motion" in the 7th grade. Cognitive material about living nature is given. Biophysical problems will contribute to the development of interest in physics. The information is presented in the form of text and illustrations.
The use of land agricultural machinery in the production of agricultural products
One of the most common methods of treating agricultural plants for protection against diseases and pests is pollination or spraying with pesticides. It is difficult to achieve a good result using ground methods. For Russian agriculture, the situation in many regions is further complicated by the fact that the farms simply do not have the appropriate equipment or it is out of order. The processing of fields in such farms becomes a big problem. But very often small aircraft come to the rescue. Aerial processing is an expensive undertaking in relation to ground processing methods, but it has many advantages.
Use of solar powered installations at home
Living without electricity is very difficult, but it takes a lot of money. Based on this, I wondered if it was possible to produce electricity without significant costs. I learned that you can use the energy of the sun, and conducted research in this direction. Collected information about which installations work due to solar energy studied them. After that, I calculated the amount of electricity consumed in my apartment and found out whether it is possible to use solar panels in it.
Investigation of shock-absorbing properties of various substances
In the work, a comparative analysis of the depreciation properties of various materials was carried out. Taking into account that the degree of pain during impact depends on the time of impact, to evaluate the latter, voltage measurements were taken between the capacitor plates. Objects of study: various types of road and floor coverings.
Study of the influence of various types of water on the growth and development of plants
The work examines the influence of "living", "dead" and holy water on the growth and development of agricultural plants.
Study of the diffusion properties of a substance in structured water
AT last years there is a growing interest in the unusual property of water - its memory, it has become the object of research by many prominent scientists. The influence of structured water on the diffusion of substances is also poorly understood. This paper describes its own method for obtaining structured water in a school laboratory and conducted experiments to study its effect on the diffusion properties of a substance.
Investigation of the dependence of the relative humidity of the air in the room on various parameters
Investigation of the dependence of the efficiency of the burner of a household gas stove on the combustion mode
The purpose of this school research project is to find out how the efficiency of a stove burner depends on gas consumption and the ratio of burner and cookware sizes. Experiments are carried out with three burners of different sizes using cookware of two diameters. In a series of experiments, water is heated on each burner with different gas flow rates (control by gas meter). For each experiment, using spreadsheets, the efficiency of fuel use is calculated, the results are presented in the form of graphs.
Research and diagnostics of nanoscale objects
Familiarization with physical methods research of micro- and nanoscale objects. Carrying out a qualitative elemental analysis of the surface of an unknown crystal structure by Auger electron spectroscopy with subsequent identification.
Research and identification of an unknown substance
In this work, a qualitative crystallographic analysis of an unknown structure by Raman spectroscopy was carried out, followed by identification.
Investigation of model properties of various models of paper planes
My passion for aircraft construction began with paper models. We made them with the whole class at the labor lesson. At the end of the lesson, the guys launched their airplanes, and I noticed that they fly differently. Some stick to a straight path, others turn to the side. I had a question: “What makes the same model fly differently?” And I decided to explore the flying properties various models paper planes. The paper describes the study of aircraft with different weight, with a different launch method, in various conditions(indoor, street).
Study of the formation of a cumulative jet
When physicists talk about cumulation, they usually mean short-term processes, such as explosions, and by cumulation they mean an increase in a certain place or direction of these processes. But cumulative jets of liquid can appear not only during explosions. Therefore, I decided to investigate the features of the interaction of "bodies of arbitrary shape with a liquid" according to the nature of the "splashes". The paper considers the conditions for the formation of a cumulative jet and the factors on which its formation depends. The objects of study were the types of splashes formed when a liquid drop falls into a liquid; when a solid ball falls into a liquid; depending on the density of the liquid and balls, their radius and height of fall, on the height of the fall of a liquid drop into the liquid, on the time between drop separations; kind of splash when a test tube falls.
The study of the density of the walrus tooth (tusk)
In the project, a study was made of the density of a walrus tooth (tusk), as well as problems about walruses.
Study of the preparation of food products for control of the content of radionuclides (strontium and cesium)
The paper presents a study of the preparation of food products for control of the content of radionuclides of strontium and cesium on the example of fish samples. The purpose of this work is to get acquainted with the laboratory, to study the methods of analysis of raw materials, semi-finished products and finished products, the study of instruments and scales in the laboratory, the radiochemical method of analyzing food samples.
Subject: technology
Grade: 2A
Program: "Primary school of the XXI century" author Luttseva E.A.
Subject. Different materials - different properties
Didactic goal: to create conditions for studying the properties of different materials that surround a person,
Tasks:
personal
cultivate love and respect for nature
contribute to the formation of the experience of joint creative activity of students
metasubject
develop research skills and abilities, the ability to work in pairs; creative thinking of students
subject
find out by experience what properties the materials known to students have: paper, fabric, wood, metal;
Means of education:
multimedia projector, presentation for the lesson
Lutseva.E.A. Technology 2 class. Textbook.- M., Ventana-Count, 2008
Lutseva.E.A. Workbook "Learning craftsmanship" - M., Ventana-Graf, 2008
samples of materials: pieces of paper, fabrics; metal plates. tree
plastic cups with water
Teaching methods: research
Forms of organization of cognitive activity:
frontal;
group;
individual.
Stage
Teacher activity
Student activities
UUD
Self-determination to activity
Guys, in the last lesson we made a doll from different materials. Tell me, could you play with a toy doll that is made of snow? chocolate? Why?
What did not suit us in these materials?
Tell me, what determines the choice of material for the product?
Today in the lesson we will conduct a study and find out what you need to know about materials in order not to make a mistake in choosing. We will work in groups (5+5+4)
The children answer that the snow doll will melt in the warmth, it will stain the hands of chocolate, and it can also be deformed.
Can you make a nail out of ice? Not
A boat made of sugar? Not
Children make guesses and guesses.
Personal:
Self-determination (motivation of learning);
regulatory:
goal setting; communicative: planning learning collaboration with teacher and peers
Knowledge update
slide number 2
slide number 3
slide number 4
Frontal work is proposed to answer the questions:
What is called material?
What is called a product?
The correctness of the answer can be checked by clicking on the link to slide No. 3
work with the textbook Read the text on p. 21 and answer the questions
Are natural resources infinite?
Material is what something is made of.
The product is the creation of human hands
Children read the text on page 21
Children's statement about caring for natural resources
communicative: planning educational cooperation with the teacher and peers;
cognitive: logical - analysis of objects in order to highlight features,
semantic reading.
Setting up learning activities
slide number 5
slides number 6, 7,8
slide number 9
You have the same images on your desk various items. Look at the pictures of the items. What groups can they be divided into? Why? Discuss in pairs. Children's responses are heard.
Check the correctness of your actions. Name which products are made from the same material?
Explain why these materials were used for these products. What are the features? What determines the choice of material for the product?
Children perform practical work on dividing objects into groups:
From wood: chair, books, board, notebook, wooden gate, chest of drawers
From fabric: curtains, T-shirt, shorts.
From metal: cutlery, drills, iron gates.
Clothing should fit, warm, absorb.
Metal products are durable.
Children make assumptions that it is necessary to know some features, characteristics of materials.
cognitive: logical - analysis of objects in order to highlight features and classification; communicative:
proactive cooperation in finding a solution to the problem;
cognitive:general educational independent selection - the formulation of a cognitive goal; brain teaser - formulation of the problem, for which we will investigate
Building a way out of difficulty
slide number 10.
slide number 11
slide number 14
slide number 15
Let's be curious and explore these materials in more detail.
We are doing research. Group work.
1. Place samples of different materials in front of you: paper, fabric, wood, metal. Consider them carefully. Tell what you see.
Take each material in your hands, remember, bend. knock. What do you feel?
What you see and feel are the properties of the materials.
In order to understand the features (properties) of materials, we will conduct their practical study, that is, we will study in detail.
2. Practical study of the properties of various materials. Conduct a study of the properties of materials. Everything you need for research is on your tables. Record the results of the study in the table.
Check the correctness of your work according to the sample. Do your answers match the sample. If not, then let's discuss.
Task: Do Research p.22
1. Acquisition and integration of knowledge - 4
2. Cooperation - 4
3. Communication - 2
4. Problem solving - 3
5. Use of ICT - 1
6. Self-organization and self-regulation - 2
Speaking in oral speech:
Material properties are what you see and feel.
Children do research with materials. Study task on page 22 of the textbook and fill out the table
Sample self-test.
regulatory: planning, forecasting; cognitive:
analysis of objects in order to highlight features, sign-symbolic actions (work with a table)
communicative proactive cooperation in the search and selection of information,
plan activities and allocate responsibilities;
regulatory: control, evaluation, correction;
perform the training task with self- and mutual verification;
cognitive:general education - ability to structure knowledge communicative: managing partner's behavior - control, correction, evaluation of partner's actions, skill
interact adequately within the educational dialogue;
- present the result of the group's activities.
Primary fastening
Read the question on page 22
Analyze the table:
Do different materials have similar properties?
Name the same properties of different materials. What material is elastic? What material with this property do you know?
How does knowing the properties of different materials help each craftsman in his work?
Children work on the table.
Yes, there are.
Change when deformed: paper, cloth
Does not tear: wood, metal.
Not deformed: wood, metal.
Fabric, rubber.
regulatory: control, evaluation, correction; cognitive: the ability to consciously and voluntarily build a speech statement, reflection of the methods and conditions of action; communicative: the ability to express one's thoughts
Assimilation of new knowledge
Creative task in a group
You have been given materials. The task is to imagine what might come of them? Think, check with the table how you can use the properties of the material.
Prove the correct choice of material.
Group work. The children fill in the cards.
Paper -
Wood -
Metal -
Textile -
regulatory: control, correction, selection and awareness of what has already been learned and what is still to be mastered, awareness of the quality and level of assimilation;
personal: self-determination
Communicative: the ability to express one's thoughts with sufficient completeness and accuracy
Reflection of activity
Guys, now you can answer the question: do different, outwardly dissimilar materials have similar properties?
What new did you learn? What have you learned? Where in life can you use this knowledge?
Which of you had a hard time? Who coped with the difficulties? Whom did the comrades help?
Rate your personal work in the group and the work of the whole group.
Give your opinion on the lesson
Continue the sentences: I did not know ...., I learned ...., I did not know how ...., I learned ....
Children's answers.
Communicative: the ability to express one's thoughts with sufficient completeness and accuracy; cognitive: reflection; personal: meaning formation
Appendix. Tables.
Material properties
What I'm researching
paper
wood
the cloth
metal
smooth
rough
rough
smooth
loose
dense
loose
dense
Yes
No
Yes
No
Does it stretch (elasticity)
No
No
Yes
No
Yes
No
Yes
No
Yes
Yes, but it doesn't sink
Yes
No, it's sinking
Yes
No
Yes
No
Material properties
What I'm researching
paper
wood
the cloth
metal
What kind of surface (smooth, rough)
What is the density (dense, loose)
Does it change when crushed (deformation)
Does it stretch (elasticity)
What transparency (see through or not)
What is the relation to moisture (wet or not)
What strength (tear or not)