Teaching Forces on a trampoline!

Posted: June 4, 2014 in Thoughts and ideas
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It can be tricky to find good examples to show how forces add up to give a resultant force. In particular, sum of vector forces in AS Physics is something that takes practice in order for students to grasp. So, when one of my boys enjoyed a ride on one of those trampolines where they strap you to two elastic ropes to make you jump very high I thought it would be useful to share this photo with you. The tensions from the two ropes pull him at the same angle on either side, but he jumps up vertically. Why does this happen? You can ask students. Then force arrows could be drawn and look at their vertical and horizontal components to see that the horizontal components are balanced and the vertical components add up, etc…

What other useful concrete examples do you use with your students?

Sorry the photo got uploaded on its side instead of the right way up, but you should be able to easily rotate it on a PPT presentation, or you could mess with you students and tell them it was taken at the Equator 😀 and see what they say!

I recently was asked about the phases of the Moon and why the Moon appears to change in shape in its orbit around the earth. So I thought a good point to start from was to establish what misconceptions people have on this topic and I found this great video by Veritasium (but I would stop it at the end of the interview without revealing the explanation initially).

The most common misconception in the video seems to be that the earth blocks the sunlight reaching the Moon, hence, we see the phases of the Moon when it is behind the earth with respect to the sun. At this point I would slide two circles of card, a white and a black one (with the black one bigger than the white one) past each other (black on top). If the black card is the shadow cast on the Moon by the earth (essentially what happens in a lunar eclipse), the shapes of the Moon due to the light reflected back to earth are considerably different than the shapes we observe from the phases of the Moon. So, we have establish that this model is a misconception.

Now we can introduce a better model and I use the pingpong ball in the image below with the students in the centre of the room. They are the observers on the earth and the light from the sun is coming from the left hand side in the photo.

If you go around the learner in the middle of the class making sure the “lit” face of the pingpong moon is always facing the wall on the left in this case, your students will see the same shapes we observe during the phases of the moon.

To reinforce this demonstration you could show the students this great animation by Keith Gibbs (also available in HTML5 if using an iPad).

Ok, now for the icing on the cake that you’ve all been waiting for! Check out the video below that shows a cresent moon through an infrared camera. You can see the crescent really bright, but you also see the other parts of the side of the moon facing the earth. I believe that is what is emitted by the moon in the infrared spectrum and that gets picked up by the IR camera. It is really awesome.

Flipping arrow – awesome refraction demonstration

Posted: April 26, 2014 in Institute of Physics, Thoughts and ideas
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When @CardiffScience posted (on Google+) a video demonstration of an arrow drawn on a piece of paper that flipped direction when seen through a glass of water I knew I had to try it myself and write this post. The video below shows the demonstration which is pretty neat, but carry on readying below the video for what I think is the explanation.

As some of you might know, I am one of the Editors of Talkphysics.org with David Cotton and he posted the below photo on this thread, which is think is a convincing explanation of what goes on in my video of the flipping arrow. If you trace the path of the three rays in the Dave’s photo you can see the ray that start from the top slit from the ray box ends up at the bottom on the multimeter. This is essentially what is happening in the video, so the light reflected by the right side of the arrow gets refracted by the water inside the glass and ends up on the left when it reaches the camera. Looking at the photo above though gave me an idea, i.e. “If I go close enough to the glass I should go beyond the focal point of the glass lens and see the arrow flipping again!” – WRONG! That didn’t actually happen. However, I just noticed that Dave’s liquid was Glycerine (at least if the name of his image file tells the truth), so I wondered whether the refractive index of glycerol was such to cause less bending inside the glass, but I was wrong again. In fact, water has a refractive index of 1.33 and glycerol of about 1.47, so there should be more bending of light inside the glass. I still haven’t figured out why I can’t flip the image again if I go close enough to the glass, but I still think it was worth posting this article and if you know the answer, please leave a comment! Thanks!

I have always found it is quite hard to show the path of the current in a bridge rectifier to A-level students using diodes alone. The diodes are tiny, for a start, and you end up following the wire with your finger around, but students seem to get lost in the process. I still introduce the rectifier using diodes and one thing I show them is that even using a DC voltmeter doesn’t change the sign. This is convincing for some, but it is still nice to be able to give further proof of what’s going on.

The diagram might also help, because it is easier to follow the path around.

However, I have started building rectifiers with LEDs alongside the diode version and it works a treat. The first thing I show them is the circuit on DC current. Only two of the four LED light up, so I can ask “What would happen, if I reverse the polarity?” They now seem to get it and they often answer correctly that the other two LED will light up. I change the polarity several times to simulate the two half-waves, as in the images below.

Then, I get the spinning wheel we use to observe ripples in the ripple tank (the one with gaps, I can’t remember the name) and put the LED rectifier on AC. The result can be seen in the video below.

A nice Pressure in Liquids question

Posted: December 6, 2013 in Institute of Physics, Thoughts and ideas
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I first was introduced to this really nice question by Neil Atkin (@natkin) and ever since I have tried to find a good way of showing it. So, look at the question and the explanation that I think is correct, as far as I can tell (but please point out any faults in my reasoning). Then, check out the simple demo I used to show this.

“If I am on a boat in a pond and I hold a 10 kg rock in my hand, what will happen to the level of the water if I drop the rock inside the pond? Will the water level increase, stay the same, or be lower?”

It’s all to do with Archimede’s Principle that states that the upward buoyant force exerted on a body immersed in a fluid is equal to the weight of the fluid displaced by the body.

This should help us think about this problem. In fact, if the boat is floating it means that the weight of the water displaced by the rock when it is inside the boat must be the same as the weight of the rock itself. That is because the upthrust balances the weight of the boat, myself and the rock, or the boat would sink. So the rock displaces a volume equivalent to the space occupied by 10kg of water, i.e. 10 litres.

When I throw the rock inside the pond the water displaced by the rock is only the volume of the rock itself, which is most likely not 10 litres, but much less. So, the level of the water in the pond decreases!

I took these two photos before and after to convince you of this (the measuring cylinder we used in another attempt was to big to appreciate the difference). Click on either photo to enlarge them and see them in Gallery view.

Anyone who insists technology is disempowering has probably not come across really young learners interacting with it. Today I was reminded about how intuitive, engaging and formative technologies like the iPad really are.

I want to call Nonna!

My 2 year old boy, Martino, felt like talking to Nonna (grandma in Italian). I say talking, but, although he can say quite a few words, he hasn’t learnt to say many sentences yet. What he has learnt to do, and very quickly, is to use an iPad. In fact, he’s so good at it that today he ran in the kitchen, took the iPad Mini and came back to the sofa looking pleased with himself. Then, he turned it on, swiped to access the apps, found FaceTime inside a folder and called my mum from the recent calls. When Matteo (my eldest) heard the ringing sound of FaceTime he asked Martino, if he was calling Nonna. “Sí, Sí!” answered Martino.

Needless to say that this unexpected call made my mum’s day, but what I’ve witnessed today, and many other times since Martino was one and a half, is something that made me think deeply about the power of technology.

Our learners are deeply engaged with technology, they grow surrounded by it and naturally embrace it as part of their learning. I believe it is essential we engage our students with technology to harness this enthusiasm our young people show for it. I heard of many primary and secondary schools that began to use iPads when they noticed their youngest learners kept touching the screen of PCs and laptops the first time they used them. iPads, smartphones and tablets are engaging and an integral part of many learners’ every day routines. They are drawn to them and naturally interact with such devices with great interest and proficiency, so using them in the classroom seems to me to be a logical way to engage children in their learning. This will make schooling more fun, but that should never be the driver for integrating technology in the classroom! iPads and other technologies open ways to redefine pedagogy and learning experiences. They empower learners and teachers, so that students become more independent and creators of knowledge, rather than simply consumers of knowledge. Let’s embrace technology for the right reasons and not thinking that the kit will solve all the teaching and learning challenges in our schools.

There are many ways to use technology creatively and innovatively to enrich our learning environments and much can be learnt from educational blogs such the CollaboratEd.org.uk Blog (@Collaborat_Ed), Neil Atkin’s Blog (@natkin), maybe this Blog you are reading and, one of my favourite, Gavin Smart’s Blog (@GavinSmart).

Literacy and Numeracy Framework and the NSP

Posted: October 9, 2013 in Free Resources, Mind Mapping, Thoughts and ideas
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You might have noticed from the changes in my profiles across the social media world that my role is changing and that I have been appointed as a National Support Programme Partner in Wales by CfBT. I will work with them four days a week and developing as an independent consultant for one day a week, so if you are looking for CPD training in your school give me a shout 😉

But back to the focus of this post. When I was preparing for my interview I was trying to get a clear picture in my mind of what the National Support Programme offers and what the role of the NSP Partners involve. If you have come across me before, you probably know that the process of getting a clear mental picture of things to me means only one thing – Mind Mapping :-). So, I made two Mind Maps that really helped me organise my thoughts around these issues. I have added the images of these two Mind Maps below, but if you are an iMindMap user, click on each image and you will be taken to the Biggerplate page where the maps are stored and where you’ll be able to download them and use with iMindMap.

The National Support Programme

The role of the NSP Partner

Self Organised Learning Environment on Minecraft

Posted: October 3, 2013 in new technologies, Thoughts and ideas
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It’s been a while since my last post, so my fingers are itching now, especially because what I am going to write about had virtually no input from me. My four boys have been completely immersed in Minecraft for quite a few months now. In particular, they love playing together on two iPads and an iPhone, so they can cooperate, send messages to each other and they’ve even made three beds in each of the houses they built, so they can sleep together in any house they find themselves in when it gets dark (and for those who are not familiar with Minecraft you better go to sleep when it gets dark, or zombies and creepers will come to get you).

A self organised geography lesson

One day my six year old invited the other two, four and eight respectively (the two year old can use the iPad very well, but on Minecraft he tends to destroy stuff, so it’s better to leave him out of a creative session 😉 ), to join him in his Olympic Games. So, they set off to build flags for each country (well, just a few actually, but I was pleased they added Italy). They found out what colours the flags for the countries they wanted to add were and made them out of Minecraft blocks. You can see the results below.

Italy

Japan

A bit of Literacy

Then, they created various games. There was a ring for sword fighting, a hurdle race track and even target shooting. The boys also placed some signs with some basic rules for the games, as you can see below.

And finally a bit of numeracy

Now it was time to mark out the difficulty of the target shooting game, so they added some signs to show how far from the target the archers should stand for an easy, medium and hard shooting session. This shows how you can develop “using number and measuring skills” through a video game that kids find incredibly engaging. So engaging, in fact, that they set off to create what became (in my opinion) a great learning journey completely independently. I believe this is a really nice example of a SOLE (Self Organised Learning Environment) that Sugata Mitra talks about and that the nature of the game, the intuitiveness of iPads and the ability to collaborate in real time from different devices facilitated this process many folds.

The power of technology

I’ve always been fascinated by the way very young learners interact with new technologies, and it was observing my nephew searching the internet when he was ten that prompted me to start this Blog, but I have never seen anything as powerful as an iPad in allowing children to create their own learning journeys. I watch my two year old who can get in and out of the apps he wants, build helicopters in the Lego app and fly them, call my mum with FaceTime (it’s true! It happened several times), etc… Then, I see my four year old who since he was three could create amazing buildings and objects in Minecraft at a speed that makes me feel dizzy, or my six and eight year old boys who use iPads to search for information they are interested in, find video tutorials on YouTube that show them how to create portals in Minecraft that take them to other worlds, etc… and I see so much that I am proud of. But I also see a fantastic tool that empowers them to learn through play. If they can learn things by themselves using these amazing technologies, think about how much more could be done in the classroom with them!

The Hidden Particles of Fishy Tank

Posted: May 17, 2012 in Institute of Physics, new technologies, Thoughts and ideas, Workshops
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In a previous post I wrote about the Fish Tank Cloud Chamber workshop funded by IoP and organized by Cerian Angharad in Cardiff and I promised I would run one in Gloucester. Well, this evening I did and all delegates had great fun taking part in the filming of the iMovie trailer you can see below. I made using an iPad third generation and it was very easy to do, because these trailers come with the storyboard already set up for you. In fact, all the clips, places for captions and duration of the trailer are fixed, which means that you really need to focus on the message you want to convey and do it in the simplest way possible. But it also prevents you from adding too much to your video. Also, I like the fact that there is no dialogue and the message is communicated entirely through the clips and captions you create!

These are important skills for any learner and I would encourage any educator with an iPad, iPhone, or iPod Touch to let their pupils create these short trailers for their learning. I got the inspiration for this one and other trailers I made by the inspiring work Gavin Smart does with his learners at Priory Community School.

#addcym chat summary from the 24th April 2012

Posted: April 24, 2012 in Thoughts and ideas, Uncategorized
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It was great to moderate the Twitter #addcym chat tonight as the topic that was picked was one I am really passionate about, i.e. Peer Coaching! We also had the privilege to have Les Foltos (@lfoltos), a World leader in Peer Coaching, joining the chat for a while and Stuart Ball (@innovativeteach) who gave some real experiential insights on the process of Peer Coaching as well as offering to run the course for teachers, and we hope to be able to take him up on that one 🙂

Another late contributor was Gavin Smart (@gavinsmart) who promised a link to his school’s video on the Peer Coaching GROW model.

There were so many contributions tonight that I am bound to omit something, so I will just give a list of the main points (according to my understanding of the chat) as bullet points!

– Some asked if the Peer Coaching process should be formal, or informal and there seemed to be a general consensus that Peer Coaching should encourage relationships of trust and non-judgemental support

– Some felt strongly that Peer Coaching shouldn’t be tied to Performance Management in order to remove the “fear” of failure and judgement. The main reasons behind this view seem to spring from the need to let the individual teacher identify targets according to their needs and interests. A set of targets prescribed from the top differs from coaching because it does not encourage reflective practice some felt!

– This led to the view that Peer Coaching should be a bottom up process, initiated by the Coachee and facilitated by the Coach. Some also identified the need to have the full commitment of SLT in terms of time and funds allocation in order to make Peer Coaching genuinely effective. Some believed that without SLT full commitment to Peer Coaching only the enthusiasts will take the lead and this would not bring whole school improvement, but only pockets of good practice!

– A good model was given by Gavin Smart’s School (Priory Community School) where “Half of all staff attend the GROW program during twilight inset at PCSA focusing on using coaching with students and staff” suggesting that a large percentage of CPD dedicated time is committed to Peer Coaching!

– Another interesting thought that was raised was whether the Coaches should be the “Experts” or ordinary teachers. This divided the discussion a bit into those who see the need to have technology savvy Coaches that are always ready to offer support and solve problems and those who believed that an “Expert” could be too threatening for some Coachee and inhibit their process. In particular, some were concerned about the potential danger that “it’s too easy to get the coachee to do what you do, rather that letting them identify their own needs”. I believe behind these reflections there is the fundamental question to be asked: “What is the role of a Peer Coach?” Les offered some truly refreshing and useful insight on this point by saying about Coaches: “Not expert with answers. Raise questions, provide support encourage teachers to solve issues. ” I am inclined to agree with this view, because if the Coach plays just the part of the expert and if they have a solution to the problems the Coachee is facing always ready, who are they encouraging the Coachee to engage in reflective practice? And without reflective practice how can the Coachee make real progress and learn to walk on their own?

– Latching on to the last point someone suggested that it is important that the Coach becomes the Coachee at some point in the Peer Coaching process. In this way the circle is closed and the “Expert” complex can be avoided.

– Some other really valuable contributions included the idea of Coaching Learners and having Learners Peer Coaching each other and/or Peer Coaching teachers. I see that idea similar to the many examples of Digital Leaders that are beginning to surface in many schools these days. Some felt that some teachers would resist the idea very strongly and feel quite uneasy about it!

I hope I have given a good account of the discussion, but feel free to correct me and add things I have missed out. Please continue the discussion in this Forum Thread on TES.