Точен topic simple machines. Методическая разработка занятия по английскому языку на тему "Машины и работа" (3 курс)

The

An inclined plane consists of a sloping surface; it is used for raising heavy bodies. The plane offers a in that the force required to move an object up the incline is less than the being raised (discounting ). 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.

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 1). 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.

Simple machines can be used to make work easier and faster. Compound machines are basically simple machines placed together to work together. Work is force acting on an object that moves it a distance (W=F*d). A simple machine must have some force applied to it to do work. Simple machines let us use a small force to beat bigger forces. They can also change the direction of the force. Keep in mind that a simple machine cannot create energy (F input * d input = F output * d output). If you want the force output to be big and distance output to be small, you need to have a big distance input and a small force input. If you want the force output to be small and the distance output to be large, then the force input needs to be large and the distance input to be small (Fd = Fd). There are three simple machines will be focus on for this project: lever, pulley, and wheel and axle. .
The lever is used in seesaws, shovels, hammers, and other everyday objects. A lever consists of three main parts: the fulcrum, rod, and the load the machine is acting on it. The fulcrum, or fixed point, allows the rod to move up and down freely. There are three classes of levers, but for this project a will be using the second-class lever. This lever allows us to use less force to act on the load. In other words, less force and more distance will be inputted to result in more force and less distance. This kind of lever in usually used to move heavy objects. The fulcrum is closer to the load to achieve this. This simple machine will probably be the best to lift the soda can. Most of the lever can be built out of wood. The fulcrum may be made out of metal or wood. .
The pulley is used in cranes. Pulleys usually lift the load. A pulley changes the direction in the force to do that. A pulley is used to change the direction of the force. It can also multiply forces depending on the type. In this project a type one and two pulley will be used.

Essays Related to Simple Machines

1.

Technology and machines have become more advanced we have grown accustomed to having machines such as computers and cars in our everyday lives. Our own machines will soon surpass our own intelligence. ... Machines have played a vital role in our lives. ... When they were first created a computer that had the power of one of today"s simple five dollar calculators required so much space to hold all of their necessary equipment it could take up a whole room, but the simple machine known today can be made so small it can not even be handled by a human due to its s...

• Word Count: 1272
• Approx Pages: 5
• Grade Level: High School

2.

AI is the attempt to make machines, specifically computers, perform intelligently through programming. ... It could be said that the human brain is nothing more than a machine, and as we know it to be capable of thought it would be fair to surmise that therefore machines can think and it is probably this, or a similar premise that inspired AI. ... This argument is an attempt to demonstrate that although a computer program appears to be understanding a story, it is merely obeying simple instructions, and has no understanding at all. ... But what are these natural causal properties, and from ...

• Word Count: 1323
• Approx Pages: 5
• Has Bibliography

3.

In The Time Machine by H.G Wells, Wells portrays the future to an exact detail. ... The Eloi are simple and beautiful creatures, but the Time Traveler thinks of them as weak and lazy. ... Through the Time Machine Wells warns that mankind will come to end if capitalism continues. ... Social Darwinism and evolution are presented throughout the Time Machine. ... Well"s uses the Time Machine to project what he believes the future will be. ...

• Word Count: 1454
• Approx Pages: 6
• Grade Level: High School

4.

Rage Against The Machine At first thought a band standing on stage naked for 15 minutes without saying a word or playing a single note might seem lewd, but after finding that they were silently protesting censorship one might think differently of them. Rage Against the Machine (RATM) is probably one of the most atypical bands that one could ever find. ... Believe it or not there are bands who care less about money and more about issues and Rage Against the Machine is one of them. ... The majority of their songs were primarily written as activist poetry by Zack de la Rocha (lead singer ...

• Word Count: 519
• Approx Pages: 2

5.

ABSTRACT Complex system theory in animals and machines is well developed and a basic synopsis is provided. ... These ideas have been applied in the field of Engineering to develop machines for controlling states of objects or events: a simple temperature control system is used as a model. ... This process, is the modern basis of the modern theory regarding the evolution of life, which in simple terms can be described as the process of prolonging a type of structure through; duplication, reproduction or other processes. ... A basic comparison of control systems in nature and machines can b...

• Word Count: 908
• Approx Pages: 4
• Has Bibliography
• Grade Level: Undergraduate

6.

Personally thinking, technology makes people"s life simpler than making people"s lives more complicated because newly developed devices, improvement of living condition and efficient transportation. ... All of those technologies can help people get a simpler and easier lives. ... Thus, technology has more benefits can be discovered, and it make lives simpler rather than more complicated. In conclusion, although technology may be a little bit complicated, when we count it use on machines, communication, information, and transportation, it is more pure and effortless for our lives. ...

• Word Count: 787
• Approx Pages: 3
• Has Bibliography
• Grade Level: Undergraduate

7.

A simple distinction between both groups is that humans depend on organization where as animals do not. The Time Machine by H.G. ... Unlike the Eloi, the Morlocks have a curiosity for knowledge which is why they take the time machine. ... When the time machine is returned to him, he notices that it is very clean and well oiled. ... Wells illustrates this quite well in The Time Machine. ...

Of course, depending on the gun. Some are a lot more simple than others. All are “simply” machines, but not all are “Simple” machines.

A matchlock, from the 1600’s was simple, very simple, and a modern electric gatling gun, not so simple.

Col. Colt literally went broke because his first revolver, the Paterson Colt was not simple enough.

He built a large supply of revolving guns, on credit, then tried to sell them to the U.S. Army, who rejected the gun as being too fragile and too complex for use in the field.

The existing muzzle-loading pistols only had 3 moving parts, all simple to get to and to repair.

The Paterson had no trigger guard. Rather, the trigger was recessed in the frame, and when the hammer was cocked, the trigger was pushed out where it could be squeezed.

Also you had a revolving cylinder, and linkage with the hammer to move the cylinder and to index the next chamber with the barrel.

And there was added linkage from the hammer, to push the trigger out into firing position and retract it afterwards.

It had well over double the number of moving parts of a single-shot, requiring more parts inventory in the field, and repairs only by a skilled armorer, when something quit working, plus possibility of powder fouling or mud jamming the cylinder. A very few initial guns were bought as a trial, then the design was rejected completely.

So, he couldn’t sell his guns to the U.S. Army, and worse than THAT, they acquired a stink that kept them from selling in the civilian market.

Since they weren’t good enough for the Army, why would anyone else want one?

That was until The Republic Of Texas came along.

Until that time, Colt Patent Firearms was nearly done for… they were already entering bankruptcy proceedings. `

Texas put in a large order, pretty much emptying that warehouse full of guns that nobody wanted except Sam Colt’s creditors.

The first thing was that the immediate money from that order saved Colt from bankruptcy by the skin of his teeth.

The next, more important thing was that The Texas Army, Texas Navy, and (especially) The Texas Rangers used them, which created the civilian market that the U.S. Army had destroyed for him.

In The Battle Of The Bay Of Campeche, the Texas Navy defeated the Mexican Navy, and as a nod to The Republic Of Texas, Colt produced the model 1851 Navy with an engraved cylinder standard, depicting this naval battle.

In addition, to creating a market, the Rangers found a few design flaws, so Captain John Coffee Hays and Capt. Samuel Walker (The Walker Colt ) went to Connecticut with plans for design changes.

The result was The Colt Patterson #5 Holster model, marketed by Colt as “The Texas Paterson”.

The original concept was that the Paterson was an infantry weapon. When you fired your five shots, you could lay flat on the ground, partially disassemble it for reloading, then re-assemble and go on fighting.

The most important use of Colt Revolvers was by The Texas Rangers, who often had to fight Indians on horseback.

To reload the gun, you had to remove the barrel wedge, then remove the barrel, then stuff powder and ball into each chamber with a special supplied tool, then follow those steps in reverse.

If the cylinder, barrel, or barrel wedge fell out of your hands, the gun was useless.

Most Rangers got around that by wearing a sash around their waist and sticking loose parts in there while they just switched in a spare loaded cylinder.

That was in addition to carrying two revolvers, so they had a better chance of getting through an encounter without having to actually stuff powder and balls into the chambers to reload.

So the two most major changes the went to Sam Colt with was to increase caliber from .28 to .36 and produce a different shape on the grip.

Then two years later, Captain Hayes campaigned for the addition of a loading lever, and a capping port in the rear, so no disassembly was required to reload on the back of a galloping horse. Colt made the change to the Texas Paterson.

The Comanche sometimes wore breastplates made of 18-inch lengths of reeds packed in dried mud, and this would often stop a light little .28 caliber ball.

Captain John Coffee Hayes (Called “Devil Jack” by local Indians) first introduced The Comanche to Colt Patent Firearms at The Battle Of Enchanted Rock , in 1841.

He was a surveyor by trade, and climbed to the top of the highest feature in the area, (Enchanted Rock) to have a good look at the lay of the land.

Unfortunately, Enchanted Rock was sacred to both the Comanche and Tonkawa tribes, who believed that evil spirits lived there and are rumored to have made human sacrifices at the base of the rock to keep from getting on the bad side of the spirits. The Comanches caught him alone up there.

In a 3-hour solo battle, he killed them until they took refuge in caves at the base of the rock.

How many of them he killed, before they hid from him, depends on whom you ask, but the lowest count is 15.

Enchanted Rock was already believed by them to be home to evil spirits, and they became convinced that those spirits were on the side of Hays, or that he was actually one OF them.

He had two Texas Patersons, a rifle and a Bowie Knife with him.

Standard Indian tactic was to goad a Ranger into shooting OR shooting AT three of them in quick succession, then charging in for a kill before any reloading of his two pistols and a rifle could happen.

That’s how it worked with two single-shot pistols and a single-shot rifle.

Enchanted Rock was their first exposure to someone who could fire 11 shots without reloading.

At one point, he killed a couple of them climbing up after him with his Bowie Knife, another piece of standard equipment for Rangers.

Engineering Connection

Why do engineers care about simple machines? How do such devices help engineers improve society? Simple machines are important and common in our world today in the form of everyday devices (crowbars, wheelbarrows, highway ramps, etc.) that individuals, and especially engineers, use on a daily basis. The same physical principles and mechanical advantages of simple machines used by ancient engineers to build pyramids are employed by today"s engineers to construct modern structures such as houses, bridges and skyscrapers. Simple machines give engineers added tools for solving everyday challenges.

Learning Objectives

After this lesson, students should be able to:

• Understand what a simple machine is and how it would help an engineer to build something.
• Identify six types of simple machines.
• Understand how the same physical principles used by engineers today to build skyscrapers were employed in ancient times by engineers to build pyramids.
• Generate and compare multiple possible solutions to creating a simple lever machine based on how well each met the constraints of the challenge.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN) , a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g. , by state; within source by type; e.g. , science or mathematics; within type by subtype, then by grade, etc .

NGSS: Next Generation Science Standards - Science

International Technology and Engineering Educators Association - Technology

Lesson Closure

Today, we have discussed six simple machines. Who can name them for me? (Answer: Wedge, wheel and axle, lever, inclined plane, screw, and pulley.) How do simple machines make work easier? (Answer: Mechanical advantage enables us to use less force to move an object, but we have to move it a longer distance.) Why do engineers use simple machines? (Possible answers: Engineers creatively use their knowledge of science and math to make our lives better, often using simple machines. They invent tools that make work easier. They accomplish huge tasks that could not be done without the mechanical advantage of simple machines. They design structures and tools to use our environmental resources better and more efficiently.) Tonight, at home, think about everyday examples of the six simple machines. See how many you can find around your house!

Complete the KWL Assessment Chart (see the Assessment section). Gauge students" understanding of the lesson by assigning the Simple Machines Worksheet as a take-home quiz. As an extension, use the attached to conduct a simple machines scavenger hunt in which students find examples of simple machines used in the classroom and at home.

In other lessons of this unit, students study each simple machine in more detail and see how each could be used as a tool to build a pyramid or a modern building.

Vocabulary/Definitions

Design: (verb) To plan out in systematic, often graphic form. To create for a particular purpose or effect. Design a building. (noun) A well thought-out plan.

Engineering: Applying scientific and mathematical principles to practical ends such as the design, manufacture and operation of efficient and economical structures, machines, processes and systems.

Force: A push or pull on an object.

Inclined plane: A simple machine that raises an object to greater height. Usually a straight slanted surface and no moving parts, such as a ramp, sloping road or stairs.

Lever: A simple machine that increases or decreases the force to lift something. Usually a bar pivoted on a fixed point (fulcrum) to which force is applied to do work.

Mechanical advantage: An advantage gained by using simple machines to accomplish work with less effort. Making the task easier (which means it requires less force), but may require more time or room to work (more distance, rope, etc.). For example, applying a smaller force over a longer distance to achieve the same effect as applying a large force over a small distance. The ratio of the output force exerted by a machine to the input force applied to it.

Pulley: A simple machine that changes the direction of a force, often to lift a load. Usually consists of a grooved wheel in which a pulled rope or chain runs.

Pyramid: A massive structure of ancient Egypt and Mesoamerica used for a crypt or tomb. The typical shape is a square or rectangular base at the ground with sides (faces) in the form of four triangles that meet in a point at the top. Mesoamerican temples have stepped sides and a flat top surmounted by chambers.

Screw: A simple machine that lifts or holds materials together. Often a cylindrical rod incised with a spiral thread.

Simple machine: A machine with few or no moving parts that is used to make work easier (provides a mechanical advantage). For example, a wedge, wheel and axle, lever, inclined plane, screw, or pulley.

Spiral: A curve that winds around a fixed center point (or axis) at a continuously increasing or decreasing distance from that point.

Tool: A device used to do work.

Wedge: A simple machine that forces materials apart. Used for splitting, tightening, securing or levering. It is thick at one end and tapered to a thin edge at the other.

Wheel and axle: A simple machine that reduces the friction of moving by rolling. A wheel is a disk designed to turn around an axle passed through the center of the wheel. An axle is a supporting cylinder on which a wheel or a set of wheels revolves.

Work: Force on an object multiplied by the distance it moves. W = F x d (force multiplied by distance).

Assessment

Pre-Lesson Assessment

Know / Want to Know / Learn (KWL) Chart: Create a classroom KWL chart to help organize learning about a new topic. On a large sheet of paper or on the classroom board, draw a chart with the title "Building with Simple Machines." Draw three columns titled, K, W and L, representing what students know about simple machines, what they want to know about simple machines and what they learned about simple machines. Fill out the K and W sections during the lesson introduction as facts and questions emerge. Fill out the L section at the end of the lesson.

Post-Introduction Assessment

Reference Sheet: Hand out the attached Simple Machines Reference Sheet . Review the information and answer any questions. Suggest the students keep the sheet handy in their desks, folders or journals.

Lesson Summary Assessment

Closing Discussion: Conduct an informal class discussion, asking the students what they learned from the activities. Ask the students:

• Who can name the different types of simple machines? (Answer: Wedge, wheel and axle, lever, inclined plane, screw, and pulley.)
• How do simple machines make work easier? (Answer: Mechanical advantage enables us to use less force to move an object, but we have to move it a longer distance.)
• Why do engineers use simple machines? (Possible answers: Engineers creatively use their knowledge of science and math to make our lives better, often using simple machines. They invent tools that make work easier. They accomplish huge tasks that could not be done without the mechanical advantage of simple machines. They design structures and tools to use our environmental resources better and more efficiently.)

Remind students that engineers consider many factors when they plan, design and create something. Ask the students:

• What are the considerations an engineer must keep in mind when designing a new structure? (Possible answers: Size and shape (design) of the structure, available construction materials, calculation of materials needed, comparing materials and costs, making drawings, etc.)
• What are the considerations an engineer must keep in mind when choosing a site to build a new structure? (Possible answers: Site physical characteristics , distance to construction resources , suitability for the structure"s purpose .)

KWL Chart (Conclusion): As a class, finish column L of the KWL Chart as described in the Pre-Lesson Assessment section. List all of the things they learned about simple machines. Were all of the W questions answered? What new things did they learn?

Take-Home Quiz: Gauge students" understanding of the lesson by assigning the Simple Machines Worksheet as a take-home quiz.

Lesson Extension Activities

Use the attached Simple Machines Scavenger Hunt! Worksheet to conduct a fun scavenger hunt. Have the students find examples of all the simple machines used in the classroom and their homes.

Bring in everyday examples of simple machines and demonstrate how they work.

Illustrate the power of simple machines by asking students to do a task without using a simple machine, and then with one. For example, create a lever demonstration by hammering a nail into a piece of wood. Have students try to pull the nail out, first using only their hands

Bring in a variety of everyday examples of simple machines. Hand out one out to each student and have them think about what type of simple machine it is. Next, have students place the items into categories by simple machines and explain why they chose to place their item there. Ask students what life would be like without this item. Emphasize that simple machines make our life easier.

See the Edheads website for an interactive game on simple machines: http://edheads.org.

Engineering Design Fun with Levers: Give each pair of students a paint stirrer, 3 small plastic cups, a piece of duct tape and a wooden block or spool (or anything similar). Challenge the students to design a simple machine lever that will throw a ping pong ball (or any other type of small ball) as high as possible. In the re-design phase, allow the students to request materials to add on to their design. Have a small competition to see which group was able to send the ping pong ball flying high. Discuss with the class why that particular design was successful versus other variations seen during the competition.

Additional Multimedia Support

See http://edheads.org for a good simple machines website with curricular materials including educational games and activities.

References

Dictionary.com. Lexico Publishing Group, LLC. Accessed January 11, 2006. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com

Simple Machines. inQuiry Almanack, The Franklin Institute Online, Unisys and Drexel eLearning. Accessed January 11, 2006. http://sln.fi.edu/qa97/spotlight3/spotlight3.html

Contributors

Copyright

Supporting Program

Acknowledgements

The contents of these digital library curricula were developed by the Integrated Teaching and Learning Program under National Science Foundation GK-12 grant no. 0338326. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government. 

Last modified: December 4, 2019