Reflection 3: Pulleys

X uses the pulley

Pulley is a simple machine consisting essentially of a wheel with a grooved rim in which a pulled rope or chain can run to change the direction of the pull and thereby lift a load.

Pulleys can be used to simply change the direction of an applied force or to provide a force/distance tradeoff in addition to a directional change.

Pulleys are clever devices that allow you to lift large weights with much smaller forces. The length of the string used to lift the pulley determines how much force is needed. For example three string lengths allow us to lift a heavy object with a force equal to 1/3rd of its weight

 In the sandpit we have a pulley system which gives force and mechanical advantage. The pulley makes work seem easier because it changes the direction of motion to work with gravity. Let's say you have to lift a heavy load, like a bale of hay, up to the second floor of a barn. You could tie a rope to the bale of hay, stand on the second floor, and pull it straight up. Or you could put a pulley at the second floor, stand at the first floor, and lift the bale of hay by pulling straight down. It would be the exact amount of work in either case, but the action of pulling down feels easier because you're working with the force of gravity.

The pulley in my centre is made up of four pulleys and one length of rope that goes around in a big loop. The idea came from another centre in the area. The bucket which is used for transporting the water and the sand is attached to the rope by a big hook.

The children use the pulley for transporting mainly sand and water,   from one end of the sandpit to the other by pulling on one rope. Today S demonstrated how he uses the pulley. In order for him to transfer the bucket of sand to the far end, he pulled on one side of the pulley until it got to the spot in the sandpit where he wanted to deposit the load. To return the bucket to where he was standing, he pulled on the other piece of rope. Children soon learn through problem solving how to effectively operate the pulley and that the system will not work if both pieces of rope are pulled at the same time.  The Children discovered that the heavier the load the stronger the pull one has to make to keep the pulley moving. Children also learn to take turns by deciding who pulls the rope and who offloads at the other end. They engage in dialogue.

 A pulley really saves effort when you have more than one pulley working together. By looping a rope around two, three, or even four pulleys, you can really cut down on the effort needed to lift something. The trade-off? Well, as you increase the number of pulleys, you also increase the distance you have to pull the rope. In other words, if you use two pulleys, it takes half the effort to lift something, but you have to pull the rope twice as far. Three pulleys will result in one-third the effort — but the distance you have to pull the rope is tripled!

I explained that the pulley system also operated the chair lifts in the mountain and for those children, who had been on chairlifts, were able to see the connection. Instead of transporting bucket loads of sand or water, the pulley operated chairlifts transport people. The chairlifts reduce the amount of time it takes a skier to move from the bottom of the hill to the top and it enables the skier to save his energy for the ride down on the slopes. The system also enables the transportation of hundreds of people all at once in a matter of minutes.

The children learn scientific terms like wheels and axles which help machines to work: they learn about the forces ,downwards and upwards ,and about gravity.   

http://www.miniscience.com/projects/pulley/

http://teacher.scholastic.com/dirtrep/simple/pulley.htm

Little machines that help us: Clogs and wheels , pulley’s and things

Technology is everything is everywhere around us – digital technology,construction,tools,machines. I sat at the table with the boys as they worked away at the clogs and wheels construction set  and enjoyed a great session  learning  with the boys about mechanical technology :about gears and axles, cranks and connectors: how things fit and what makes  the gears go round. This experiences enabled the boys  how to assemble basic building blocks and then moving on to more challenging activities , for example how to make improvements  or change the mechanics of something.

  S had seen an example of a device which C had built  and which could be useful for calling the three little pigs home in the story of “ The three little pigs and the big bad wolf”which the children had been reading at mat time.

S chose to build  something quite different and after carefully selecting through the various photographs of things to build, he chose to build a gear pane.

S was  very focused on this activity and took the time to look  carefully at the pictures on the photograph to improve the gear plane after he built up the basic structure. He wanted to extend the wing span and we discussed the various parts : crank, gears, connector and  towers which could be used to solve the problem. I carefully demonstrated what each part was useful for .We learned  from the internet that the crank  is a device consisting of a arm or handle  to transmit motion  or starting a motor, the gear is a saw toothed mechanical part that engages with a similar part to transmit motion rotating from one body to another. and connectors are useful for attaching parts together.The the tower could be used for making things longer or taller.

S problem solved how to extend  his gear plane by adding more towers. He also added gears in front of the plane and demonstrated how they move. I demonstrated how the two gears  moved in opposite directions and when two gears are connected by a third gear and , the third gear will move in the direction  of the first gear – something I had to think about myself!

I was impressed with S's concentration as he wanted to complete his piece in order to be able to show and tell.It gave him a sense of ownership.

Construction technology involves the design of structures , tools and material (Fleer& Jane,2011), and in his own little way ,S discovered the basics of construction technology. S discovered that by using different parts, he could change or improve his piece of construction .The technology that was involved : thinking about the process, the design and searching for a solution.

“ Children experience an environment where they learn strategies for active exploration, thinking, and reasoning (p.88) “and experience the stories of their own and other cultures” (`Ministry of Education, 1996,p78).

I liked the creativity that came out of this exploration. Fleer and Jane (2011) maintain that creativity and imagination are important aspects which help children to broaden their experiences.This was clearly demonstrated in the finished product of the children.

I know that S valued this one on one exploration with me and it gave him a sense of competence at having achieved something.

Fleer,M., & Jane, B. (2011). Design and technology for children. Frenchs Forest, N.S.W: Pearson Australia.

Ministry of Education. (1996). Te Whāriki: he whāriki mâatauranga mo nga mokopuna o Ăotearoa: Early Childhood curriculum. Wellington, New Zealand: Learning Media.

the device built by C

 
http://annlm-annlm.blogspot.com/

Digital Technology in Early Childhood

http://annlm-annlm.blogspot.comThe use of technology can be used to record and analyse, and share how children learn. For example McNaughton and Williams talk about how digital cameras, audio and video recordings, computers, laptops and photocopiers assist in this way. Educators can use digital recorders and phones to make recordings of conversations, work in progress, dramatic play which can be reviewed at a later date and analysed.

Children can make their own audio and video recordings, for example their musical creation and video recording. Such happened today (09/11) at the Centre. In the course of the week, the children had been listening to the story of the Three Little Pigs using a storybook CD while the teachers used props to aid in the story telling. This was followed by the children re-enacting the story which was videotaped on camera and replayed back to the children.  It was interesting to note how special they were feeling to see themselves “on TV” so to speak! The children were able to see themselves as story tellers.

Today (10/08) teacher C left the video camera in place with music in the background and asked the children to make their own play of a rock band. Some were fascinated to see themselves live on screen strumming on their guitars and moving to the music. C and A made transformers and told their own story.

In addition, digital photos taken are easily uploaded onto journals or portfolios or printed in various ways, even used to create slide shows which are another way of sharing the child’s learning experiences. Not only those, the child can revisit and talk about it. Furthermore the information can be shared via email or a website. (McNaughton and Williams).

Smorti  (1999) defines technology as helping people and solving problems... through the development of products, systems or environments. Solution to problems are met through combining the knowledge skills and resources

It is evident that the technology allows us to give information and to be entertained. Children begin to understand that TV is not a box to go in, and that we can use a video camera to capture photos which is relayed back as an image. C also demonstrated how this can be done with the use of a laptop which has been fitted with a camera. Another demonstration involved connecting the laptop to a TV screen and showing for example a documentary of a volcanic eruption from the internet.

Children develop the ability to represent their discoveries using creative and expressive media and the technology associated with them (Ministry of Education,) they develop experience with some technology.

Technology allows for change and opportunity in early childhood in a world which is becoming increasingly technological.To give children the best chance in life, educators will need to broaden their own ideas of technology.  

McNaughton, G., & Williams. (2009). Techniques for teaching young children: choices in theory and practice (3^rd ed.).Frenchs Forrest, NSW, Australia: Pearson Prentice Hall.

Ministry of Education. (1996). Te Whāriki: he whāriki mâatauranga mo nga mokopuna o Ăotearoa: Early Childhood curriculum. Wellington, New Zealand: Learning Media.

Smorti,S.(1999). Technology in Early Childhood, Early Education, No 19Autumn1999.http://rosebud.blogspot.com