5 MECHANISMS THAT CONTROL MOTION

MECHANISMS THAT CONTROL MOTION

Direction control: ratchets.

A ratchet is a mechanism that controls the direction of motion.

Speed reduction: brakes.

Brakes use friction to reduce speed. They are activated by certain levers. The lever transmit forceto an output receptor, which puts pressure on wheeel. This produces friction, which slows down the wheel.

3 TRANSFORMATION OF MOTION

TRANSFORMATION OF MOTION

Some mechanisms transform linear motion into rotary motion. Most of these mechanisms are reversible. They also transform rotary motion into linear motion.

Rotary-linear transformation

Wheel
Wheels are esssential parts of bicycles. They let us move more easily because they reduce our contact with the ground and decrease friction.

Rack and pinion mechanism
A rack is a bar with many teeth and a pinion is a gear with teeth that interlock with the rack.When the pinion rotates, the rack moves in a linear direction.

Nut and bolt mechanism
A nut and bolt mechanism transforms rotary motion into linear motion. A bolt or shaft with a spiral groove and a nut that turns around it.

Winch and crank mechanism
A winch is a cylinder that rotates around a horizontal axis. The crank increases the force and the winch transforms rotary motion into linear motion. This mechanism has the Law of the Lever.                        

Reciprocratin rotary-linear

The pedal mechanism of a bicycle transforms the reciprocating movements of our legs into continuous.

Crank and rod mechanism

The piston moves a rod forwards and backwards. This rod turns the first wheel. The second wheel turns because it is connected to the first wheel by annother rod.

Crankshaft mechanism

We can connect multiple rods to one shaft. The rods are connected to cranks, and the cranks are connected to the crankshaft.

Cam mechanism

A cam is an irregulary shaped device that rotates on a shaft. When the cam rotates, it pushes a special bar called a follower. The follower can move other parts or it can turn a switch on and off.

2 ROTARY TRANSMISSION

ROTARY TRANSMISSION

These mechanisms have two purposes:

• Transferring rotary force from an imput location to another location.
• Changing the rotary speed by using rotating elements of different sizes.

The relatonship between the speeds of the two wheels in inversely proportional to their sizes.

                                                       N1/N2=D1/D2 

This relationship is called the ratio of transmission, where N is the speed of rotation and D is the diameter of the wheel.

To calculate the ratio of transmission between the first wheel and the last wheel of a belt drive, we must multiply the ratios of transmission of the first pair of wheels and the second pair of wheels:

                                              N4/N1=D1 X D3/D2 X D4

We use different types of gears when two axes are parallel, perpendicular or crossed.

2 LINEAR TRANSMISION

LINEAR TRANSMISION 

Linear transmision mechanisms:use linear motion input to produce linear motion output. We typically use these mechanisms to transmit force.

- A lever is a rigid bar that turns around a point called a fulcrum.When the forces acting on opposite ends of a lever are equal, we say the lever is in equilibrium.

F x d= R x r

- Classes of levers: The locations of the fulcrum, force and resistance divide levers into 3 classes.

CLASS 3: Levers increase the distance that the end of the lever moves.CLASS 2: Levers increase the force that we apply.CLASS 1: Levers can do both of those things.CLASS 3:

CLASS 2:

CLASS 3:

Pulleys and compound pulley systems:
A pulley is a wheel that rotates around an axis and has a groove and a compound pullley system is a combination of fixed and movable pulleys. It is also called a block and tackle system.

Fixed pulley                                                                              Movable pulley

Force=Resistance                                                                      Force=Resistance/2



Vertical and horizontal systems                                                 Exponential system

F=R/2 x n                                                                                      F=R/2^n

1 WHAT IS A MECHANISIM?

The parts of a mechanism

1st Input of force and motion
2nd Mechanism
3rd Output force and motion

Mechanisms transmit and transform force and motion from an input source (motor) to an output receptor.

MECHANISMS

5 CREATING INFORMATION

The most popular tools for creating and distribuing information on the Internet are web pages, blogs and wikis.

5.1 Web pages

Steps you must follow are:

1. Register a domain
2. Sing up with a host server
3. Design and create your web page
4. Upload your page to the server
5. Update your page regularly 

Domain names
To register a domain for your web page, you must choose a name that is not already being used.

Host servers
Companies such as Arsys and Nominalia host web pages by offering space on their servers.

Designing and creating a web page:
This will make your web page more attractive: title, colour combinations, a balanced layout, hyperlinks, visual impact, comments from users, page order.

Uploading a web page to a server
You can use a FTP (File Transfer Protocol) programs to upload your web page to the server.

Completing and updating a web page
If the content is always up to date, people will continue visiting your web page.

5.2 Blogs

They were originally used as online diaries for people. Nowadays many blogs are 'opinion generators' about a variety of other topics.

5.3 Wikis

A wiki is a collection of web pages that visitors can edit

4 SHARING INFORMATION

Social networks are virtual enviroments for comunnication, interaction and the sharing resources.

4.1 Horizontal social networks

Facebook allows a groups of 'friends' to publish both public and private messages with text, links, fotos, vídeos...
Twitter has some unusual features. Users publish short text messages (tweets) with no more than 140 characters.
Google+ allows users to create 'circles' of friends in order to share information.

4.2 Vertical social networks

Sharing professional information: LinkedIn
Sharing general information: FriendFeed
Sharing photos: Instagram, flickr
Sharing videos: YouTube, Vimeo, Dailymotion
Live streaming: Skype, livestream

3 MANAGING INFORMATION

3.1 Social bookmarking

Social bookmarking is an internet tool that lets us organise, use and share information more efficiently. It works in a way that is similar to the Favourites option of a browser program. All of our content is stored in the cloud.
Most popular social bookmarking applications:
Delicious is a service that lets us save our favourite web pages along with a description and a list of key words for easier clasification.
Diigo defines itself as a 'multi-toolfor Knowledge management'.
Evernote provides a convenient workspace where we can collect information by capturing articles and images from the internet.

3.2 Working in the cloud
The most popular cloud-based services are Google drive, Dropbox and OneDrive.
The two main advantages of these services are:
=>Access to our files from any location or device with an internet connection
=>The ability to share our files easily with other people.

2 FINDING INFORMATION

2.1 Web pages
A web page is a collection of documents that can include text, audio, video, images and hypertext links to other web pages. A browser is a program that locates a web page by its address and lets users access the content.

A search engine is a web page with a database of information about other web pages and their content.

2.2 News feeds: Rich Site Summary (RSS)

RSS is a subscription service that provides users with frequent updates from media websites, blogs and other sources of information.

RSS news feeds are conveinment and time-saving. People can subscribe in two ways:
>Directly from the web page
>Through a news aggregator program(online or downloable)

PERSONAL LEARNING ENVIROMENT

-Finding information
-Managing information
-Sharing information
-Creating information

1. WEB 1.0, WEB 2.0 AND WEB 3.0

• WEB 1.0

-It was in the 90s
-It was a network of documents
-People could notinteract with the content
-The information online was not updated very frecuently
-Almost everything that people used online was also part of the World Wide Web (www)

• WEB 2.0

-During the 1st decade of the 21st century
-Information became bidirectional (receive information but also create and share it)
-New services appeared and became popular, such as email, chats, videoconferences, forums, blog, wikis and programs for person to person (P2P)

• WEB 3.0

-From 2006 onwards
-New technologies allowed the integration of data and the web
-Programs could 'understand' and work with the information
-Cutting edge developments formed the basis of technological evolution : artificial intelligence (AI); aplications that don't use a browser, virtual reallity, and GPS

The web

In this unit you will learn to:

• Understand your Personal Learning Enviroment (PLE).
• Differentiate the characteristics of Web 1.0, Web 2.0 and Web 3.0.
• Recognise how digital information can be found, managed and shared.
• Create information by publishing web pages, blog and wikis.
• Use the cloud to store and share information.
• Understand and use applications for mobile devices.
• Improve your Personal Learning Enviroment (PLE).

Technology

Helloo!!! This is my new blog. I have my personal blog called "El blog de Mario". This blog is going to be about technology.