Давние topic simple machines. Методическая разработка занятия по английскому языку на тему "Машины и работа" (3 курс)
Topics: Simple machine , Mechanical advantage , Force Pages: 5 (856 words) Published: September 22, 2013
Activity 1.1.2 Simple Machines Practice Problems Answer Key
Procedure
Answer the following questions regarding simple machine systems. Each question requires proper illustration and annotation, including labeling of forces, distances, direction, and unknown values. Illustrations should consist of basic simple machine functional sketches rather than realistic pictorials. Be sure to document all solution steps and proper units.
All problem calculations should assume ideal conditions and no friction loss.
Simple Machines – Lever
A first class lever in static equilibrium has a 50lb resistance force and 15lb effort force. The lever’s effort force is located 4 ft from the fulcrum.
1.Sketch and annotate the lever system described above.
2.What is the actual mechanical advantage of the system?
3.Using static equilibrium calculations, calculate the length from the fulcrum to the resistance force. FormulaSubstitute / SolveFinal Answer
A wheel barrow is used to lift a 200 lb load. The length from the wheel axle to the center of the load is 2 ft. The length from the wheel and axle to the effort is 5 ft.
4.Illustrate and annotate the lever system described above.
5.What is the ideal mechanical advantage of the system?
FormulaSubstitute / SolveFinal Answer
6.Using static equilibrium calculations, calculate the effort force needed to overcome the resistance force in the system. FormulaSubstitute / SolveFinal Answer
A medical technician uses a pair of four inch long tweezers to remove a wood sliver from a patient. The technician is applying 1 lb of squeezing force to the tweezers. If more than 1/5 lb of force is applied to the sliver, it will break and become difficult to remove.
7.Sketch and annotate the lever system described above.
8.What is the actual mechanical advantage of the system?
FormulaSubstitute / SolveFinal Answer
9.Using static equilibrium calculations, calculate how far from the fulcrum the tweezers must be held to avoid damaging the sliver FormulaSubstitute / SolveFinal Answer
Simple Machines – Wheel and Axle
10. What is the linear distance traveled in one revolution of a 36 in. diameter wheel? FormulaSubstitute / SolveFinal Answer
An industrial water shutoff valve is designed to operate with 30 lb of effort force. The valve will encounter 200 lb of resistance force applied to a 1.5 in. diameter axle.
11.Sketch and annotate the wheel and axle system described above.
12.What is the required actual mechanical advantage of the system? FormulaSubstitute / SolveFinal Answer
13.What is the required wheel diameter to overcome the resistance force? FormulaSubstitute / SolveFinal Answer
Simple Machines – Pulley System
A construction crew lifts approximately 560 lb of material several times during a day from a flatbed truck to a 32 ft rooftop. A block and tackle system with 50 lb of effort force is designed to lift the materials.
14.What is the required actual mechanical advantage?
FormulaSubstitute / SolveFinal Answer
15.How many supporting strands will be needed in the pulley system? FormulaSubstitute / SolveFinal Answer
A block and tackle system with nine supporting strands is used to lift a metal lathe in a manufacturing facility. The motor being used to wind the cable in the pulley system can provide 100 lb of force.
16.What is the mechanical advantage of the system?
FormulaSubstitute / SolveFinal Answer
17.What is the maximum weight of the lathe?
FormulaSubstitute / SolveFinal Answer
Simple Machines – Inclined Plane
A civil engineer...
You May Also Find These Documents Helpful
Essay about Simple Machines
HanicalSimple Machines and its Mechanical Advantage What are Simple Machines ? What do we mean by Mechanical Advantage? Simple Machines * creates a greater output force than the input force Therefore since work is performed by applying a force over a distance, with the use of these machines we can do more work with lesser effort than working with our bare hands. In short, they make work easier. Mechanical Advantage * The Ratio between the input force and the output force. * The measure of the force amplification achieved by using a tool, mechanical device or machine system. Anyway what is input and output force? Input refers to the force you applied while output refers to the resultant force the object has from the input force. Example: I pushed a ball with 10 N of force, it is rolling with 10 N of force. I input 10 N into it, now it is outputting 10 N. The Six Classical Simple Machines The Lever(French word that means “to raise”) * A simple machine that allows you to gain a mechanical advantage in moving an object or in applying a force to an object. It is considered a "pure" simple machine because friction is not a factor to overcome, as in other simple machines . Part | Description | Fulcrum | Is where a solid board or rod can pivot...
Simple Machine Essay
...Simple Machine Joemarie A. Martinez 1-D CE Simple machine Simple machines make work easier by multiplying, reducing, or changing the direction of a force. The scientific formula for work is w = f x d, or, work is equal to force multiplied by distance. Simple machines cannot change the amount of work done, but they can reduce the effort force that is required to do the work! As you can see by this formula, if the effort force is reduced, distance is increased. These simple machines fall into two classes: (i) the inclined plane, wedge, screw characterized by the vector resolution of forces and movement along a line, and (ii) the lever, pulley, wheel and axle characterized by the equilibrium of torques and movement around a pivot. Wedges and screws are both a type of inclined plane; pulleys and wheels and axles are both a form of lever A simple machine is an elementary device that has a specific movement (often called a mechanism), which can be combined with other devices and movements to form a machine . Thus simple machines are considered to be the "building blocks" of more complicated machines . This analytical view of machines as decomposable into simple machines first arose in the Renaissance...
Simple Machines Essay
...Simple Machines Definitions: Machine - A device that makes work easier by changing the speed , direction, or amount of a force. Simple Machine - A device that performs work with only one movement. Simple machines include lever, wheel and axle, inclined plane, screw, and wedge. Ideal Mechanical Advantage (IMA)- A machine in which work in equals work out; such a machine would be frictionless and a 100% efficient IMA= De/Dr Actual Mechanical Advantage (AMA)- It is pretty much the opposite of IMA meaning it is not 100% efficient and it has friction. AMA= Fr/Fe Efficiency- The amount of work put into a machine compared to how much useful work is put out by the machine ; always between 0% and 100%. Friction- The force that resist motion between two surfaces that are touching each other. What do we use machines for? Machines are used for many things. Machines are used in everyday life just to make things easier. You use many machines in a day that you might take for granted. For example a simple ordinary broom is a machine . It is a form of a lever. Our country or world would never be this evolved if it wasn"t for machine . Almost every thing we do has a machine involved. We use machines ...
Simple Machine A machine with few Essay
... Simple Machine : A machine with few or no moving parts. Simple machines make work easier. Examples: Screw, Wheel and Axle, Wedge, Pulley, Inclined Plane, Lever Compound Machine : Two or more simple machines working together to make work easier. Examples: Wheelbarrow, Can Opener, Bicycle Inclined plane: A sloping surface, such as a ramp. Makes lifting heavy loads easier. The trade-off is that an object must be moved a longer distance than if it was lifted straight up, but less force is needed. Examples: Staircase, Ramp Lever: A straight rod or board that pivots on a point known as a fulcrum. Pushing down on one end of a lever results in the upward motion of the opposite end of the fulcrum. Examples: Door on Hinges, Seesaw, Hammer, Bottle Opener Pulley: A wheel that usually has a groove around the outside edge for a rope or belt. Pulling down on the rope can lift an object attached to the rope. Work is made easier because pulling down on the rope is made easier due to gravity. Examples: Flag Pole, Crane, Mini-Blinds Screw: An inclined plane wrapped around a shaft or cylinder. This inclined plane allows the screw to move itself or to move an object or material surrounding it when rotated. Examples: Bolt, Spiral Staircase Wedge: Two inclined planes joined back to back. Wedges are used to split things....
Simple Machines Examples With Pictures Essay
Applied Force Other First Class Lever Examples Applied Force Action Force Spring Load Force Action http://library.thinkquest.org/J002079F/lever.htm Third Class Lever Effort or Applied Force Egg ready to be launched Release hook Compressed Spring Load or Resistance Fulcrum Applied force can be in any direction http://www.usoe.k12.ut.us/curr/science/sciber00/8th/machines /sciber/lever3.htm http://www.usoe.k12.ut.us/curr/science/sciber00/8th/machines /images/tweezer.gif http://www.usoe.k12.ut.us/curr/science/sciber00/8th/machines /images/base.jpg Inclined Plane An inclined plane is a slanted surface used to raise an object. An inclined plane decreases the size of the effort force needed to move an object. However, the distance through which the effort force is applied is increased. The Big Rock rolling downhill with gravitational force IS NOT an example of an inclined plane. The inclined plane gives you mechanical advantage AGAINST gravity. Big Rock http://www.sirinet.net/~jgjohnso/simple.html An example of how an Inclined Plane can be used to raise a mass to activate another simple machine Egg ready to be launched By First Class Lever F Big Rock Force pushing (or pulling) Big Rock up the hill Inclined Plane First Class Lever Wedges Pulleys Wedges are moving inclined planes that are driven under loads to lift Pulleys use a wheel or set of wheels around which a single length (not...
Essay on Simple Machines
...Simple machines are extremely important to everyday life. They make stuff that is normally difficult a piece of cake. There are several types of simple machines . The first simple machine is a lever. A lever consists of a fulcrum, load, and effort force. A fulcrum is the support. The placing of the fulcrum changes the amount of force and distance it will take in order to move an object. The load is the applied force. The effort force is the force applied on the opposite side of the load. Levers can be placed in three classes. The 1st class levers are objects like pliers where the fulcrum is at the center of the lever. The 2nd class of levers are objects that have the fulcrum on the opposite side of the applied force like a nutcracker. The 3rd and final class is objects like crab claws. These objects of the load at one end and the fulcrum on the other. An inclined plane is another simple machine . Inclined planes are also known as ramps. Ramps make a trade off between distance and force. No matter how steep the ramp, the work is still the same. A winding road on a mountain side is a good example of a ramp. Some simple machines are modified inclined planes. The wedge is one of those machines . One or two inclined planes make up a wedge. Saws, knives,needles, and axes are made from wedges....
Practice Acl Problem Answers Essay
Chapter 7 ← Problem 7-43 - ACL Problem Solution a. There are 44 payroll transactions in the Payroll file. (This is determined by reading the number at the bottom of the screen.) b. The largest and smallest gross pay amounts for September are $4,395.83 and $1,278.33, respectively. (Use Quick Sort.) c. Total gross pay for September was $99,585.46. (Use the Total command.) d. The report on the following page shows gross pay by department. (Use the Summarize command on the Gross Pay column, save to a file, and print.) Note that this screenshot was produced using the “Screen” option in the Output tab of the Summarize window. Students’ hardcopy printouts will appear slightly different, but will contain the same departmental totals. e. There are no exceptions in the calculation of net pay for September. (Use the following Filter: Gross Pay – Taxes < > Net Pay.) f. There are no duplicate check numbers. (Use the Duplicates command on the check number column). There are four missing checks (#12389- #12392). The audit concern is that there may be unrecorded payroll transactions. (Use the Gaps command on the check number column.) Report for requirement d: Chapter 8 Problem 8-41 – ACL Problem Solution a. The following is a printout of the Statistics command for Inventory Value at Cost: Field: Value...
Simple Regression Model Practice Problems Essay
Chapter 4 Simple regression model Practice problems Use Chapter 4 Powerpoint question 4.1 to answer the following questions: 1. Report the Eveiw output for regression model . Please write down your fitted regression model. 2. Are the sign for consistent with your expectation, explain? 3. Hypothesize the sign of the coefficient and test your hypothesis at 5% significance level using t-table. 4. What percentage of variation in 30 year fixed mortgage rate is explained by this model? Why? Use Chapter 4 Powerpoint question 4.2 to answer the following questions: 5. Report the Eveiw output for regression model Based on the estimation period of 1986.01 – 1999.07. Please write down your fitted regression model. 6. Is Trend correlated with USPI? Set up the hypothesis testing at 5% significance level. 7. What percentage of variation in USPI is explained by this model? Why? 8. Based on your Eview model, report your forecast of USPI for the period of 1999.08-2000.07. Report RMSE. Use Chapter 4 Powerpoint question 4.3 to answer the following questions: 9. Report the Eveiw output for regression model USPIt = (USTBR)t + t based on the estimation period of 1986.01 – 1999.07. Please write down your fitted regression model. Dependent Variable: USPI | | | Method: Least Squares | | | Date: 01/24/11 Time: 16:46 | | | Sample:...
The wheel and axle , the inclined plane , the wedge , the , and the screw . Several of these simple machines are related to each other. But, each has a specific purpose in the world of doing work.
There are special tools for measuring the force necessary to move an object. These are known as force meters. They use a spring and a hook to determine how much pull is required to slide an object up an inclined plane. Really very simple to use.
Compound Machines
Simple machines can be combined together to form compound machines. Many of our everyday tools and the objects we use are really compound machine . Scissors are a good example. The edge of the blades are wedges. But the blades are combined with a lever to make the two blades come together to cut.
A lawnmower combines wedges (the blades) with a wheel and axle that spins the blades in a circle. But there is even more. The engine probably works in combination of several simple machines and the handle that you use to push the lawnmower around the yard is a form of a lever. So even something complicated can be broken down into the simplest of machines.
Take a look around you — can you figure out what simple machines make up a can opener, the hand cranked pencil sharpener, the ice dispenser in the refrigerator or the stapler? Just be careful, though. In our modern times, many things rely on electronics and light waves to function and are not made of simple machines. But even then, you may be surprised. The turntable in your microwave oven is a wheel and axle. The lid to the laptop is connected to the pad by a hinge or lever.
Simple machines may be simple — but they are simply everywhere.
A Word or Two About Rube
Rube Goldberg was a famous cartoonist who lived between 1883 and 1970. His life was spent creating art and sculptures, but his most famous work was for his "inventions." These inventions were a series of simple machines put together in a complex fashion to accomplish something very simple, but it took many steps to get there. Contests have been run for many years since Mr. Goldberg first created his unique ideas. In the contests people try to come up with new ways to turn on a light, or start a toaster using these combinations of the simple machines to wow judges and audiences for their unique way of doing these simple tasks.
Rube Goldberg machines are fun to watch and to build. Visit this site for some fun — see if you can identify each of the simple machines as they work together in this animation of a Rube Goldberg gadget designed to get this guy out of bed in the morning. Click .
For more information about Rube Goldberg"s life and his art, click .
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 . |
Or . However, some of the most important and useful machines are quite simple. In fact, scientists even call them simple machines!
So what is a simple machine? Is it a machine that does a simple , such as addition or ? Maybe it"s just a machine that"s really easy to operate, like an old television remote control? Or could it be any machine that makes life easier?
While simple machines do make our lives easier, they"re much older than either television remotes or calculators. Simple machines are some of the first machines ever created.
Since the earliest human beings walked on Earth, they looked for ways to make the of everyday life easier to accomplish. Over time, they did this by inventing what has become known as the six simple machines.
Wedges are moving inclined planes used to lift or separate. Wedges are usually used to cut, tear, or break an object into pieces. Common wedges include knives, axes, saws, scissors, and shovels. However, wedges can also be used to hold things in place, such as in the case of staples, nails, shims, or doorstops.
A is a twisted version of an inclined plane. It allows movement to be translated into an up or down motion that takes up less space. Screws can also help hold things together. Common examples of screws include jar lids, drills, light bulbs, and bottle caps.
These six simple machines are all around us. Often more machines, also called machines, consist of one or more of the simple machines put together. Can you imagine how much easier life became after the invention of these simple machines?
Topic: Simple Machines PSSA: 3.4.7.C / S8.C.3.1
Objective: TLW compare different types of simple machines. TLW compare different types of simple machines. TLW explain the difference between a simple machine and a compound machine. TLW explain the difference between a simple machine and a compound machine.
MI #1: Levers A lever is a simple machine that has a bar that pivots on a fixed point called a fulcrum. A lever is a simple machine that has a bar that pivots on a fixed point called a fulcrum. Levers are classified based on the location of the input force, load, and the fulcrum. Levers are classified based on the location of the input force, load, and the fulcrum.
MI #2: Classes of Levers First class levers have the fulcrum between the input force and the load. First class levers have the fulcrum between the input force and the load. - Includes see-saws Second class levers have the load between the input force and the fulcrum. Second class levers have the load between the input force and the fulcrum. - Includes wheelbarrows Third class levers have the input force between the load and the fulcrum. Third class levers have the input force between the load and the fulcrum. - Includes hammers and fishing poles
Mi #3: Pulleys A pulley is a simple machine that has a grooved wheel that holds a rope or a chain. A pulley is a simple machine that has a grooved wheel that holds a rope or a chain. There are three types of pulleys; fixed, movable, and block and tackle. There are three types of pulleys; fixed, movable, and block and tackle.
MI #4: Wheel and Axle A wheel and axle consists of two circular objects of different sizes that rotate on the same axis. A wheel and axle consists of two circular objects of different sizes that rotate on the same axis. The axle rotates a smaller distance than the wheel, which results in a greater output force. The axle rotates a smaller distance than the wheel, which results in a greater output force.
MI #5: Inclined Planes An inclined plane is a straight slanted surface. An inclined plane is a straight slanted surface. A wedge is a pair of inclined planes that move. A wedge is a pair of inclined planes that move. A screw is an inclined plane wrapped around a cylinder. A screw is an inclined plane wrapped around a cylinder.
MI #6: Compound Machines A compound machine is a machine that is made of two or more simple machines working together. A compound machine is a machine that is made of two or more simple machines working together. Because compound machines have more moving parts, their mechanical efficiency is typically low. Because compound machines have more moving parts, their mechanical efficiency is typically low.
So What…? Real Life Application Machines make work easier, so it is important to understand the different types of simple machines. Machines make work easier, so it is important to understand the different types of simple machines.
Рекомендуем также
Полезные и лечебные свойства иван-чая, заготовка, ферментация и противопоказания
Лада-Матушка (Матерь Сва) Лада – богиня любви и красоты
К чему снится пожар: основные толкования сновидения Если снится огонь пожар
Размер оплаты труда председателю тсж, страховые взносы и налоги
Программа «Молодая семья» в Уфе и Республике Башкортостан
Рецепты борщевой заправки на зиму со свеклой и морковью, с капустой и без
Loading...