He defeated topic simple machines. Methodical development of classes in English on the theme "Machines and work" (3 year)
) The steeper the slope, or incline, the more nearly the required force approaches the actual weight. Expressed mathematically, the force F required to move a block D up an inclined plane without friction is equal to its weight W times the sine of the angle the inclined plane makes with the horizontal (θ). The equation is F = W sin θ.
In this representation of an inclined plane, D represents a block to be moved up the plane, F represents the force required to move the block, and W represents the weight of the block. Expressed mathematically, and assuming the plane to be without friction, F = W sin θ.The principle of the inclined plane is used widely-for example, in ramps and switchback roads, where a small force acting for a distance along a slope can do a large amount of work.
The
A lever is a bar or board that rests on a support called a fulcrum. A downward force exerted on one end of the lever can be transferred and increased in an upward direction at the other end, allowing a small force to lift a heavy weight.
All early people used the lever in some form, for example, for moving heavy stones or as digging sticks for land cultivation. The principle of the lever was used in the swape, or, a long lever pivoted near one end with a platform or water container hanging from the short arm and counterweights attached to the long arm. A man could lift several times his own weight by pulling down on the long arm. This device is said to have been used in Egypt and India for raising water and lifting soldiers over battlements as early as 1500 bce.
The
A wedge is an object that tapers to a thin edge. Pushing the wedge in one direction creates a force in a sideways direction. It is usually made of metal or wood and is used for splitting, lifting, or tightening, as in securing a hammer head onto its handle.
The wedge was used in prehistoric times to split logs and rocks; an is also a wedge, as are the teeth on a saw. In terms of its mechanical function, the screw may be thought of as a wedge wrapped around a cylinder.
The
A wheel and axle is made up of a circular frame (the wheel) that revolves on a shaft or rod (the axle). In its earliest form it was probably used for raising weights or water buckets from wells.
Its principle of operation is best explained by way of a device with a large and a small gear attached to the same shaft. The tendency of a force, F, applied at the radius R on the large gear to turn the shaft is sufficient to overcome the larger force W at the radius r on the small gear. The force amplification, or, is equal to the ratio of the two forces ( W:F) and also equal to the ratio of the radii of the two gears ( R:r).
If the large and small gears are replaced with large- and small-diameter drums that are wrapped with ropes, the wheel and axle becomes capable of raising weights. The weight being lifted is attached to the rope on the small drum, and the operator pulls the rope on the large drum. In this arrangement the mechanical advantage is the radius of the large drum divided by the radius of the small drum. An increase in the mechanical advantage can be obtained by using a small drum with two radii, r 1 and r 2, and a pulley block. When a force is applied to the large drum, the rope on the small drum winds onto D and off of d.
A measure of the force amplification available with the pulley-and-rope system is the velocity ratio, or the ratio of the at which the force is applied to the rope ( V F) to the velocity at which the weight is raised ( V W) This ratio is equal to twice the radius of the large drum divided by the difference in the radii of the smaller drums D and d. Expressed mathematically, the equation is V F /V W = 2R/(r 2 - r one). The actual mechanical advantage W/F is less than this velocity ratio, depending on friction. A very large mechanical advantage may be obtained with this arrangement by making the two smaller drums D and d of nearly equal radius.
The
A pulley is a wheel that carries a flexible rope, cord, cable, chain, or belt on its rim. Pulleys are used singly or in combination to transmit and motion. Pulleys with grooved rims are called sheaves. In, pulleys are affixed to shafts at their axes, and power is transmitted between the shafts by means of endless belts running over the pulleys.
One or more independently rotating pulleys can be used to gain mechanical advantage, especially for lifting weights. The shafts about which the pulleys turn may affix them to frames or blocks, and a combination of pulleys, blocks, and rope or other flexible material is referred to as a. The Greek mathematician (3rd century bce) is reported to have used compound pulleys to pull a ship onto dry land.
The
A screw is a usually circular cylindrical member with a continuous helical rib, used either as a fastener or as a force and motion modifier.
Although the Pythagorean philosopher (5th century bce) is the alleged inventor of the screw, the exact period of its first appearance as a useful mechanical device is obscure. The invention of the is usually ascribed to Archimedes, but evidence exists of a similar device used for irrigation in Egypt at an earlier date. The screw press, probably invented in Greece in the 1st or 2nd century bce, has been used since the days of the Roman Empire for pressing clothes. In the 1st century ce, wooden screws were used in wine and olive-oil presses, and cutters (taps) for cutting internal threads were in use. 
Are made in a wide variety of diameters and lengths; when using the larger sizes, pilot holes are drilled to avoid splitting the wood. are large wood screws used to fasten heavy objects to wood. Heads are either square or hexagonal.
Screws that modify force and motion are known as. A screw jack converts (turning moment) to thrust. The thrust (usually to lift a heavy object) is created by turning the screw in a stationary nut. By using a long bar to turn the screw, a small force at the end of the bar can create a large thrust force. Workpiece tables on are moved linearly on guiding ways by screws that rotate in at the ends of the tables and mate with nuts fixed to the machine frame. A similar torque-to-thrust conversion can be obtained by either rotating an axially fixed screw to drive a rotationally fixed nut along the screw or by rotating an axially fixed nut to drive a rotationally fixed screw through the nut.
This article was most recently revised and updated by Robert Curley, Senior Editor.M.V. Rudakova (Irkutsk)
Methodical development of a lesson on the topic "Machines and Work" (Machines and work)
annotation
This lesson is conducted when studying the topic: "Machines and work" with studentsIII course (1 semester) in the specialty110809 "Mechanization of agriculture". The lesson is designed according to the textbook. Bgashev V.N., Dolmatovskaya E.Yu. English for students of engineering specialties. Students have already passed the basic stage of training in the discipline, and they already have enough lexical and grammatical material to study a professional-oriented English language program. The lesson is intended for an advanced stage of training in the English language and provides a communicative professional orientation of training. On this topic, students have already studied the basic lexical and grammatical material, so the type of lesson issystematization and generalization of knowledge. All stages of the lesson are based on uniform methodological principles, develop the main types of foreign language speech activity, and form the intercultural competencies of future specialists. The lesson uses the technology of communicative learning and the technology of learning in collaboration, as well as the technology of critical thinking. To achieve this goal, cognitive methods of motivation, volitional methods (self-esteem and correction, reflection of behavior), as well as the brainstorming method, are used. At the stage of building the project, students are encouraged to use, as a technique, a mental map (Mind Map). Particular attention was paid to the study of the lexical aspect, since the student should be able to translate professional texts, communicate on professional topics; independently improve and replenish the vocabulary.
All stages of the lesson contribute to the development of speech, language and professional competence and the achievement of set educational and educational goals.The subject of the assessment is the skills and knowledge provided by the Federal State Educational Standard for the disciplineEnglish language aimed at the formation of general and professional competencies.
Theme of the lesson:Machines and Work
The purpose of the lesson:create conditions for the development of communicative competence.
Objectives of the lesson:educational:to form lexical speaking skills, develop semantic reading skills (viewing, search, learning); developing:to develop memory, attention, thinking, logical thinking and language conjecture, learning to analyze, generalize, group); educational;to educate a cognitive interest in learning a foreign language, to form group work skills.
Formed competencies:OK 1. To understand the essence and social significance of your future profession, to show steady interest in it.
OK 3. Make decisions in standard and non-standard situations and bear responsibility for them.
OK 4. To search and use the information necessary for the effective implementation of professional tasks, professional and personal development.
OK 5. Own an information culture, analyze and evaluate information using information and communication technologies.
OK 6. Work in a team and team, communicate effectively with colleagues, management, consumers.
Occupation Type:systematization and generalization of knowledge.
Interdisciplinary communications: Russian language, physics, mechanics, machines, mechanisms.
Class equipment: textbook, projector, computer, screen, presentation, handout, Whatman paper, felt-tip pens, magnets.
Forms of work: individual, group, frontal
Stages of the lesson. Forms of work
The content of the lesson. Possible methods and techniques of execution
The main types of educational activities
UUD, formed at this stage
Teacher activities
Students activities
The stage of motivation for educational activities
Organizing time
(2 minutes.)
T. Good morning, students! I`m glad to see you. It is really fine day today, isn’t it? How are you today? What about the weather today? Is it fine? Let`s start our lesson.
The teacher welcomes students, checks their readiness for class.
Students are involved in foreign language communication, reacting to the teacher’s remarks, according to the communicative task.
Personal:adequate motivation for educational activities; the formation of motivation to learn a foreign language; the formation of a positive attitude towards the occupation of a foreign language.
Regulatory:self-assessment of readiness for the lesson.
Communicative:listen and respond to the cue adequately with the speech situation.
Lexico-phonetic exercises
(7 min.)
Electricity, effort, motion, distance, rate, weight, horsepower, watt, kilowatt, force, work wind, water, steam, petroleum, prime mover, windmill, turbine, generator, steam engine, internal combustion engine, electric motor
The teacher offers students to pronounce words for the development of pronunciation skills.
Students pronounce the words which they can use later in their speech,working on pronunciation. Correlate the graphic and sound image of English words.
Regulatory:exercise self-control of correct pronunciation.
Cognitive:to extract the necessary information from the listened.
Speech immersion
(7 min.)
T. Thank you! Great! Now, students look at the screen, here you can see the car. Let`s try to name the parts of this car and describe them using the model: This is / these are .... N + is / are made of ...
For example: this is a windscreen. The windscreen is made of glass.( application 1 )
The teacher organizes immersion in a foreign language environment, reinforces the skills of using familiar lexical units and a grammatical model.
Students, using previously studied lexical units, describe the car, naming the parts of the car and the materials from which they are made.
Communicative: listen and consciously perceive the speech of other students, carry out the correction of incorrect answers.
Acquaintance with the topic of the lesson, communication of goals
(2 minutes.)
T. Students, as you know a machine is a device that transmits and changes force or motion into work. A machine can be very simple or very complex. Terms like work, force, and power are closely connected with machines. I think you`ll try to guess what our lesson will be about. Well, what shall we do today? Yes, you`re right, we`ll speak about machines and work. We must give the definitions of the words - work, force, power and connect them with "work" and "machines". Is the topic interesting for you?
The teacher enables students to independently determine the topic of the lesson, goals, and what is needed for this.
Students independently determine the topic and purpose of the lesson using the core vocabulary.
Cognitive:be able to adequately, consciously and arbitrarily build a speech utterance in oral speech.
Regulatory:determine the purpose of learning activities with the help of a teacher; plan your actions to accomplish tasks.
II. Stage of updating of basic knowledge
Lexical work
(10 minutes.)
T. 1) To begin with I propose you to divide the following words into three groups, those which describe: 1) basic terms of physics and mechanics; 2) energy sources; 3) mechanisms, machines. ( application 2)
2) The following verbs are often related with basic terms of physics and mechanics. Now, students try to make up word combinations using these verbs: to produce, to transform, to supply, to result in, to exert, to set, to perform, to result from, to measure ... in. Model: to transmit motion / force( application 2)
The teacher activates familiar vocabulary, adjusts students' answers as necessary.
Students independently perform assignments using previously studied lexical units. Their answers are entered in the table. Check and correction of the completed task.
Communicative: conscious construction of speech utterances, reflection.
Regulatory:study of the conditions of the educational problem, discussion of solutions.
Cognitive:argumentation of their point of view.
Speaking, prediction
(4 min.)
T.Look at the screen, here you can see the terms. The task is to match each one with its correct definition.
(Appendix 3)
The teacher checks the correctness of the assignment.
Students select a definition for each term.
Brain teaser:
Cognitive:be able to analyze information.
III. The stage of independent work with a self-test on the model
Semantic reading
(14 min.)
T.Well done. Let`s continue our lesson. Read the text “Machines and work”, try to focus on its essential facts, and choose the most suitable heading below for each paragraph: 1) Prime movers 2) Definition of “machine” 3) The relationship between “work” and “force »4) Power and its measures.
You also should find the definitions of basic terms connected with "machines" and "work". Text A is on page 192 .
The teacher informs students about the reading work algorithm.
Students read the text with an understanding of the main content, select headings for paragraphs and find definitions of the basic concepts related to “work” and “machines”.
Brain teaser:develop skills to focus attention, guessing and logic.
Regulatory:improve semantic reading skills using lesson vocabulary.
Cognitive:develop semantic reading; search and highlight the necessary information; be able to structure knowledge.
Self-test and self-esteem
(5 minutes.)
T.Time is running. Let`s check your tasks.
The teacher controls how students argue their point of view, adjusts their answers.
Students discuss the text they read, give definitions of the basic concepts associated with “work” and “machines”.
Regulatory: be able to correctly evaluate the results of their work and classmates.
Communicative:be able to listen to each other to perceive the necessary information and to maintain a conversation.
Speaking Group work
(12 min.)
T. Well, let`s go on. Now, students, we`ll have a group work. I will give you some questions about the text and you should answer them.( application 4)
The teacher divides students into two groups and gives questions for discussion.
Students are divided into two groups and draw out questions on the text they have read. Discuss questions and answers to them. Use ready-made speech materials for registration of answers.
Communicative:participate in the work of the group, carry out mutual control and mutual assistance; Be active in collaboration to solve common problems.
Cognitive: be able to compare and select information from the text, consciously build verbal utterance in oral form.
Personal:to form cooperation skills, to show initiative.
IV. Project Build Phase
Readingin order to extract special information (group work)
(15 minutes.)
T.Students, your task is to give a short report about "Machine, Work, Power."
The teacher sets the task for the groups to prepare a message “Machine, work, power” using an active dictionary, which was compiled during the lexical work at the stage of updating the basic knowledge. The teacher offers students a piece of paper for writing their message.
Students make a mental map using information from the text and a table (Appendix 2),distribute who will talk about what.
Communicative:participation in the work of the group: distribution of duties, planning of their part of the work, mutual control, mutual assistance; registration of your thoughts with regard to the learning task.
Cognitive:the ability to analyze, group facts, build logical reasoning; the ability to highlight the main facts, omitting secondary ones.
Personal:show initiative and independence, strive to improve their own speech culture.
Regulatory:accept and save the training task, compare the results of your work with the results of others.
V. Stage of verification of the implementation of the constructed project
Project Verification
(8 min.)
T.So, it`s time to begin to represent your projects.
The teacher determines the level of assimilation of the necessary knowledge.
Students talk about the basic concepts of physics and mechanics, mechanisms and sources of energy and show their relationship with machines and work. Their messages are accompanied by a demonstration of the project on a piece of paper (Mind Map).
Cognitive:the ability to consciously build verbal speech in an oral form, improve speech skills.
Communicative:form your own opinion and position; to argue their point of view; participate in the work of the group.
IV. Stage of reflection of educational activity in the lesson
Summing up the work
(1.5 minutes)
T.Now we come to the end of the lesson. Do you remember the topic? What did we study today? What was new for you? Let’s review the new vocabularies in chain.
The teacher asks questions. Grades for the lesson, comments, motivates for further successful work.
Students answer teacher questions and express their opinions.
Regulatory:the ability to control their activities according to the results, the ability to adequately understand the assessment of the teacher, classmates.
Personal:ability to evaluate their activities; show a desire to improve their own speech culture in general.
Reflection
(1.5 minutes)
T.Do you like our lesson? Are you in a good mood at the end of the lesson? Do you like your work today?
The teacher invites students to express their opinion about the lesson.
Students build statements that express opinions, answer questions to teachers. Master the forms of personality reflection. ( Appendix5)
Homework
(1 minute.)
T.Your homework is the ex.26, p.203. You should fill the table.
The teacher explains what needs to be done in the homework process.
Students write down homework.
conclusions
Lesson of the English language on the III course on the topic"Machines and Work" (Machines and work) is the occupation of systematization and generalization of knowledge on this topic.
At the stage of the organizational moment, the teacher creates a general positive attitude for the upcoming lesson, helps students organize their own learning space. In this lesson, the principles of personality-oriented, developmental learning are implemented, self-assessment and mutual evaluation of students is carried out. Teacher activities are more represented in the form of organization of work and assistance to students in various educational situations.
At the main stages of the lesson, system-activity and communicative approaches are used. When summarizing and reflecting, it is planned to discuss the activities of students in the lesson, self-assessment and mutual evaluation of work results, whereby students learn the skills of analysis, evaluation of their work and others, the ability to participate in a dialogue, respectfully speak about the activities of others.
During the lesson (along with the educational ones), vital and practical tasks were also solved, the students ’life experience was used to develop their cognitive activity and independence.
List of references
Bgashev V.N., Dolmatovskaya E.Yu. English for students of engineering specialties. M .: Astrel AST, 2013.381 s.
Dubinina V.G.. Personality // English. Everything for the teacher. 2014. No1. S.14-20.
Internet resources - Wikipedia. free encyclopedia.
Chernukhina A.E. English-Russian technical dictionary. M.: ONYKS, 1997.1026 s.
Appendix 1
Let`s try to name the parts of this car and describe them using the model: This is / these are .... N + is / are made of ...
For example: this is a windscreen. The windscreen is made of glass
Bonnet - hood
Wing mirror - Side mirror
Windscreen - windshield
Rear-view mirror - rearview mirror
Windscreen wiper - "janitor"
Door - a door
Boot - trunk
Tire - tire
Wheel - wheel
Headlight - headlight
Bumper - bumper
License plate – number platesign
Indicator - turn indicator
Appendix 2
1) Divide the following words into three groups, those which describe: 1) basic terms of physics and mechanics; 2) energy sources;
3) mechanisms, machines:
Electricity, effort, motion, distance, rate, weight, horsepower, watt, kilowatt, force, work wind, water, steam,
petroleum, prime mover, windmill, turbine, generator, steam engine, internal combustion engine, electric motor
2) The following verbs are often related with basic terms of physics and mechanics. Try to make up word combinations using these verbs:to produce, to transform, to supply, to result in, to exert, to set, to perform, to result from, to measure ... in. Model: to transmit motion / force.
Active vocabulary
application
Nouns and combinations with the nouns
Verb combinations
1. Basic terms of physics and mechanics
electricity
effort
motion
distance
rate
weight
horsepower
watt
kilowatt
force
work
to produce electricity
to exert effort
to set in motion
to result in motion
to hold up the weight
to exert force
to produce work
to perform work
to result from
2. Energy sources
wind
water
steam
petroleum
3. Mechanisms and machines
Prime mover
windmill
turbine
generator
steam engine
internal combustion engine
electric motor
Appendix 3
Match the term with its correct definition:
Machine
the rate at which work is performed.
Prime mover
a device that uses force to accomplish something.
Force
an effort that results in motion or physical change.
Work
a machine whose input is natural source of energy.
Power
a combination of the force and the distance through which it is exerted.
Appendix 4
Questions for the first group:
What is a simple definition of a machine? What is more technical
definition? What does this definition imply?
Describe some very simple machines. Name some complex machines.
What do we call machines whose is a natural source of energy? What natural
sources of energy do you know and what machines use them?
Why aren`t electric motors prime movers?
Questions for the second group:
What is force? Give some examples of force.
What is work? How can work be expressed mathematically?
Give an example.
What is power?
How is the rate of doing work usually given in the English-
Speaking countries? Why was the term invented?
In what terms is power measured in the metric system?
Appendix 5
A simple machine is a mechanical device that consists of a minimum of moving parts but yet can create an improvement of the output over the input. The improvement could be creating a mechanical advantage or simply changing the direction of the output. Mechanical advantage is the increase of force, distance or speed from the input value.
Around the 16th century, the classic list of simple machines was determined. The list consisted of the lever, wheel and axle, pulley, inclined plane, wedge, and screw.
These simple machines can be broken into three classifications: lever simple machines, rotating simple machines, and inclined plane simple machines.
Questions you may have include:
- What do lever simple machines do?
- What do rotating simple machines do?
- What do inclined plane simple machines do?
This lesson will answer those questions. Useful tool: Units Conversion
Lever simple machines
The lever simply consists of a rod or board that pivots on a fulcrum, creating a mechanical advantage or a change in direction.
The lever is a classic simple machine that achieves a mechanical advantage according to the ratio of the output or load arm of the lever divided by the input or effort arm.
The mechanical advantage of a lever can concern force, distance, or speed of the output.
The efficiency of the lever is very high, since the loss due to friction at the fulcrum is low.
Rotating simple machines
Rotating simple machines include rollers, wheel and axle, crank, and pulley.
Rollers
The wheel or roller by itself can make it easier to move objects by overcoming friction.
Wheel and axle
When an axle is added to a wheel, a torque on the axle increases the speed of the outer surface of the wheel. Likewise, turning the wheel from its outer edge increases the force applied from the axle.
Crank
A crank is like a wheel and axle. You can push on the handle of a crank, and it will create a twisting force or torque on the axle. This is a variation of the wheel and axle.
Pulley
A pulley is a wheel and axle, that uses a rope to lift objects. A major purpose of a pulley is to change the direction of the input force. You can pull down one a pulley rope, and the rope will lift the object upward.
Complex set of pulleys
A complex set up pulleys, such as a block-and-tackle configuration, can result in a mechanical advantage. The question is that if it is a complex set, is it still a simple machine? Probably not.
Inclined plane simple machines
Variations of an inclined plane include a ramp, wedge, and screw.
Ramp
The inclined plane or ramp makes raising a weight to a given height easier, according to the angle of the incline. Unfortunately, the resistive force of friction from sliding the object on the ramp can negate the mechanical advantage.
Variations of the inclined plane are the wedge and screw.
Wedge
Although a wedge is considered a simple machine, it is really a special application of an inclined plane.
Screw
The screw is really an inclined plane that is wrapped around a shaft. Turning the shaft around its central axis transforms rotational motion and torque into axial motion and force.
A screw can also act like a wedge, forcing itself into a softer material.
Summary
Simple machines usually exchange using a smaller force over a greater distance to move a heavy object over a short distance. The work required is the same, but the force required is less. The are also simple machines that help to reduce the resistance of friction or such.
Make it your mission to benefit your community
Simple machines are tools that make work easier. They have few or no moving parts. These machines use energy to work. There are six types of simple machines. The six types of simple machines are used in our daily life. Simple machines convert a smaller amount of force exerted over a larger distance to a greater amount of force exerted over a shorter distance, or vice versa. The concept of simple machine was introduced by the Greek philosopher Archimedes the 3rd century.
There are six types of simple machines. The six types of simple machines are
- Wedge
- Lever.
Pulley is wheels and axles with a groove around the outside
A pulley needs a rope, chain or belt around the groove to make it do work
Examples:Flag post, Elevator, Window blinds, Crane, Winch.
A screw is an inclined plane wrapped around a shaft or cylinder.
The inclined plane allows the screw to move itself when rotated
Examples:Screw lid jar, drills, door lock, meat grinder, brace and bits,
3) Wedge:
A wedge is used to split an object through the application of force. It is made up of two inclined planes which meet to form a sharp edge. Wedges are used to split things.
Examples: Knives, ax. Forks, pin, chisels.
An inclined plane is a flat surface that is higher on one end, which makes it easier to move heavy objects to a certain height.
Examples: Roller coaster, stirs, sloping roads, ramps, boat propeller,
The wheel and axle is made up of two circular objects. The wheel is the larger object which turns around the smaller object the axle. The axle is a rod that goes through the wheel which allows the wheel to turn,
Examples: Door knobs, Egg beater, Steering wheels, door knobs, pencil sharpener. Gears are a form of wheels and axles
6) Lever:
This is a is a bar rests on a turning point. The turning point is the fulcrum. An object the lever moves is the load. There are three kinds of levers, First order, Second order and third order.
In a first class lever the fulcrum is in the middle and the load and effort is on either side.
Example: see saw
In a second class lever the fulcrum is at the end, with the load in the Middle.
Example: wheelbarrow
In a third class lever the fulcrum is again at the end, but the effort is in the middle.
Example: Pair of tweezers.
Advantage of using the six simple machines:
These six simple machines are used in day to day life. They make the work easier for us. Simple machines are being used hundreds of years before. Even the great pyramids were build by using the simple machines. The inclined plane was used to move heavy stones for building the pyramids. Different combinations of these six simple machines can be used in the building of complex machines.
Sub topics
The effort is the force applied to the machine.
The load is the force against which the machine does the work.
This ratio is a measure of the advantage that one obtains by using the machine. If a load of 40 N is moved by applying an effort of 10 N on the machine then the mechanical advantage of the machine is given by
Velocity Ratio (V.R)
The "corresponding distance" is the distance moved by the load in the same time as the distance moved by the effort.
The velocity ratio depends only on the design of the machine and is always the same for a particular machine. The mechanical advantage on the other hand can vary for a particular machine as it depends on friction.
M.A., V.R. and efficiency have no units as they are ratios between similar quantities.
Effort: The force applied to the machine.
Load: The force against which the machine does the work.
Since the effort does the work on the machine and the load is worked upon by the machine, efficiency can also be expressed as
The efficiency is very often expressed as a percentage i.e.
It should be noted that 100% efficiency is possible only for an ideal (imaginary) machine. Usually, for all practical purposes the efficiency of a machine is always less than 100%. This is because practical M.A. is always less than theoretical M.A. due to friction and the weight of the moving parts.
Easier - A simple machine is a device that helps make work easier; a device that makes it easier to move something. Some simple machines are a wheel, a pulley, a lever, a screw, and an inclined plane. Harder - Most machines consist of a number of elements, such as gears and ball bearings, that work together in a complex way. No matter how complex a machine, it is still based on the compounding of six types of simple machines. The six types of machines are the lever, the wheel and axle, the pulley, the inclined plane, the wedge, and the screw. 
Background Information for Simple Machines from National Museum of Science and Technology, Canada http://www.science-tech.nmstc.ca/english/schoolzone/Info_Simple_Machines.cfm Here you can find the answers to some commonly asked questions about simple machines. The Elements of Machines: Simple Machines from Leonardo "s Workshop http://www.mos.org/sln/Leonardo/InventorsToolbox.html Learn about devices that make work easier to do by providing some tradeoff between the force applied and the distance over which the force is applied. Also provides a brief introduction to uses of a gear, cam, crank and rod, chain and belt, and the ratchet. Levers from Beakman & jax http://www.beakman.com/lever/lever.html Play with levers and find out how work from the fulcrum to the load to the effort. (Wait for second page to come)
Marvelous machines http://www.galaxy.net:80/~k12/machines/index.shtml This website provides a series of experiments about simple machines: levers, wheels and inclined planes. They were developed for third grade students. ( Comes up slowly)
| After exploring some or all of the websites below, complete one or more of these activities: Investigate Wheels with Your Bicycle. Go to PBS Teachersource "s website and use your bicycle to learn about the wheel. Find Out How Stuff Works.Check out How Stuff Works. Look for a device that uses a simple machine as part of how it works. Create a poster showing how it works. Gear Up with a Tricycle & Bicycle. Visit PBS Teachersource "s site and follow the procedures there to learn a lot more about gears. Complete a Simple Machines WebQuest. Follow or adapt the procedures found at one of these webQuest sites: 1) Exploring Simple Machines by Paula Markowitz (Grade 4) http://www.lakelandschools.org/EDTECH/Machines/Machines.htm 2) Simple Machines http: // www.eng.iastate.edu/twt/Course/packet/labs/wheels&leverLab.htm 3) Simple Machines WebQuest (Grade 4-6) http://www.plainfield.k12.in.us/hschool/webq/webq8/ jjquest.htm 4) Simple Machines http://www.beth.k12.pa.us/schools/wwwclass/mcosgrove/simple.htm 5) Simple Machines Webquest http://www.jsd.k12.ak.us/ab /el/simplemachines.html Complete an Online Simple Machines Activity. Learn more about simple machines by following the directions at A Time for Simple Machines. You may also want to test your knowledge at Gadget Anatomy. Complete Some Simple Machine Experiments. Find lots of experiments at sites like Marvelous Machines and Motion, Energy and Simple Machines. |