## Posts Tagged ‘Photoelectric Effect’

I have touched on the idea of using Poetry in Physics on my blog post My top five list of features in Office 2007!, but this looks at the issue in more depth and it was a must to write it just one day before the National Poetry Day.

October the 7th will be the National Poetry Day and people across the UK will celebrate poetry. What better way to celebrate than getting your students to engage in Poetry in ways and areas they might have never thought possible?

Last year I used the Math Add-in for Word 2007 to create graphs of the Photoelectric Effect and then asked, in the same worksheet, my pupils to put in rhymes what the graph meant and how it explained the Photoelectric Effect. Obviously, it would have been unfair to ask them to do Poetry and coward away from it myself, so I created the instructions for their task as a poem too (a pretty bad, but maybe not so bad for an Italian with English as a second language). The results were quite remarkable and I was pleasantly surprised to see such good Physics in their explanations and such nice rhymes too.

Here is the task I set for my students:

Equation and graph created with Math Add-in

The red line was added by one of the students in response to the second part of my rhymed instructions, see below.

If this is the Photoelectric equation,

Name its parts with some persuasion!

Kinetic energy, Planck’s constant and even work function

Which symbols and Greek letters go in conjunction?

At this point they had to list the symbols associated to the Photoelectric Effect equation. Then the task carried on:

Ok, you know your symbols and letters in Greek,

Another challenge lies ahead for you Geek!

The metal is swapped with one of work function much higher,

In red the new graph draw, if this knowledge you want to acquire!

Don’t rush it and take your time

To have some fun and give it a go

And it doesn’t end there, because one of the best poems came from a student who was supposed to be Dyslexic! His poem is below.

The photoelectric effect is easy

UV light hits the metal causing it to become a little queasy

The metal releases a photoelectron without a fight

More electrons are released when the intensity is increased of the light

As long as the threshold frequency is met

The electrons would be emitted I bet

The threshold frequency for a given object

Is the minimum frequency needed for photoelectric emissions to collect

To escape the potential well

The electron must do a certain amount of work to excel

The work function can be defined

As the minimum work needed to remove an electron blind

That is all you need to know

about the photoelectric effect and potential well

When u hear of this effect

Just think how it could be in your subject

The students went on to merge the best parts of each poem created to form a rap that they then sang and recorded using SongSmith, which can be downloaded free of charge from all teachers on the Partners In Learning Network.

If you want to know more about the Math Add-in and how you could use it with your classes have a look at the Innovid I made below!

## Physics and Drama? you must be jocking! Rolls-Royce Science Prize 2008-2009

Posted: September 19, 2009 in Rolls-Royce Science Prize
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On the night of the 6th October 2009 myself and Matt Smith (John Ivins cannot attend) will represent the Physics Department (Croesyceiliog School, Cwmbran, Wales) at the Rolls-Royce Science Prize Award Dinner in the London Science Museum. We are one of nine finalists across U.K. and we are hoping to receive 1st Prize, obviously! But the competition is very tough, as the quality of the projects submitted is outstanding. So, we are up for a real challenge and a lot of heart ache.

As we are approaching the event I wanted to share with you some outlining features of our projects (underneath), and I wil post again after the dinner, hopefully with good news!

Rolls-Royce Science Prize 2008

Croesyceiliog School

Notes to the video diary

Building our modulated circuit (June 2008)

The first stage of our project was to get our pupils to research, design and build a modulated laser out of a commercial and very cheap laser pen. We wanted our pupils to actually build something, because we realised that modern devices become increasingly complex and that people perceive them as “magical boxes” that can perform amazing tasks without having any understanding of how that device really works. What we found when our pupils managed to build their modulated laser pen was that they were amazed they could actually make something they didn’t even know was possible (like sending music through a laser), and they were really gobsmacked when they realised how simple their design was. In fact, when we found a design that seemed plausible, many members of the class and, I have to confess, some teachers too were sceptical about it. They thought it would not work. In fact, our design was far too simple to perform features that to many would seem high-tech, like sending an audio signal with a laser pen across a room and play the music from a receiving light sensor and speaker. However, and thankfully, our design exceeded our expectations, as it didn’t just work, but the sound was clear and very loud once we input it into a larger amplifier! Our pupils were extremely excited and could not stop playing with the device after they built it.

The above diagram shows how we designed our modulating circuit. The input signal from an MP3, I-pod, CD player, etc is sent across the resistor. As this is an A.C. signal it will cause a variation in the voltage across the resistor, which in turn will cause the overall current in the circuit of the laser pen to change with the same frequency as the input signal. This overlaps with the D.C. supply current from the laser battery, which will cause the intensity of light in the laser diode to change with the same frequency. So, now our laser beam keeps varying in intensity and can be sent to a light sensor which is attached to our mini-amplifier. Because the number of photons reaching the light sensor changes with the frequency of the input signal, the current generated by the photoelectric effect in the light sensor will also change with that frequency and because now there is an A.C. signal sent into the mini-amplifier the cone of the speaker is moved by the motor effect and we can hear the sound at the other end of the lab. The capacitor in the modulating circuit is essential to let the A.C. signal through and block the D.C. current from the battery of the laser to feedback into the audio device. To many this sounds like magic, but it is in fact quite a simple process, that can be used to explain a wide range of Physics topics, like our pupils did in the next stage of their project! What I like about our device is that it is very cheap and very visual. You could buy a similar set up from a well known retailer for about £250, but we managed to make ours for about £15. And that allowed us to stay well within budget and also to make gift boxes containing our device for the schools we visited. Also, you can see exactly how our device is made, because we decided to keep it nice and simple, just soldered together and not even mounted on a circuit board, so that even the least Scientifically minded could see how the circuit was connected.

Communicating the Physics behind our device (June 2008)

When we brainstormed how to use this device to demonstrate Physics concepts within the teachers involved in the project, we thought our pupils could design a lecture type show with lots of involvement from the audience. But when we put it to them they came up with a much more creative idea! They decided they were going to write a play based on the James Bond theme and use the various situations arising in the different acts to explain the Physics concepts behind our device. In their play they also made space for interactive demonstrations where they would ask members of the audience to participate in the demonstrations. This was highly effective and very innovative. In fact, even in modern Theatre acts you don’t often see the audience actually taking part in the play! The script our yr 12 pupils wrote was amusing, engaging and full of sound Physics. In fact, our pupils decided to address an audience of younger children (Yr 9 pupils) to motivate them to appreciate Physics more and with the hope they will consider studying Physics at A-level, or Degree level.

In the various acts our yr 12 pupils were able to explain concepts from the GCSE Curriculum, such as signal modulation, Visible Spectrum as a means of Communications, Optical Fibres and reflection of light, and some A-level topics, like the Photoelectric Effect. In this last demonstration, which was put in simple and very visual terms, our yr 12 stretched the Yr 9 pupils beyond GCSE and showed them that A-level Physics can be interesting and also accessible to them. In fact, they explained the Photoelectric Effect so well that even some pupils with Additional Educational Needs could understand how the process works!

The script is self explanatory and reading it should give a very clear idea of how these concepts where presented and the level of engagement and interactivity of our show. You can read the script in the appendix to these notes!

During these visits to schools our yr 12 pupils demonstrated and employed high degrees of team work. In fact, with very little rehearsals (timetable constraints disallowed us to spend enough time to rehears and plan the logistics of the play) and no time at all to get used to new environments, they could always put up a very sound and professional performance (although none of them was a Drama student). For example, we went to a school in Torfaen that made the wooden stage in their gym available to us. So, we started to set up the laser pen and receiver on stage, when we realised that the wooden blocks sagged considerably every time you would move on them disaligning the laser beam and light sensor, as the stage was very old! So, our pupils had to think on their feet and work together to move everything quickly to the best location off stage where it could still be visible. At the end they decided to use the stage for some parts of their show and the floor underneath for others, showing great initiative. Another example is when we went to a school in Newport and we were asked to perform in a Science lab (an environment completely different from the gym), and again our pupils worked well and creatively together in solving problems such as darkening the room and setting up all scenes successfully!

Our yr 12 pupils’ perception of Physics changed too. In fact, one girl that was not achieving her real potential said that after she had to write and present the Photoelectric Effect to a younger group she started to really understand the phenomenon, while she couldn’t before. This is exactly the kind of experience we as teachers face every day. It is only when we have to teach others that we start to understand thoroughly the topics we present. Another girl in Yr 12 who was always unmotivated in class really sparked in this project and became so involved that she soon took leading responsibilities for the completion and gathering together of the script. She was not sure if she wanted to stay to do Physics in yr 13, but after our project she has decided for it. Our project also consolidated the choice of pursuing a Physics, or Engineering Degree for the rest of the yr 12 pupils.

What did people think? (July 2008 to February 2009)

We visited several schools across Torfaen and Newport and in all those our pupils were praised for the quality of their show and for the knowledge and understanding they demonstrated and could effectively transmit to their younger audience.

Most pupils from the audience told us they enjoyed the play and that it was a much more fun way to learn about Physics. They also liked the fact that older pupils and not teachers were showing them these concepts, as they could relate to them more.

The teachers’ comments were very positive and the Head of Science in Caerleon School (Newport) said that although the Photoelectric Effect might have been too difficult for her Yr 9 class, they will remember that demonstration when they study it at A-level and that will become a memorable experience that could be very valuable in their development. Also, she was impressed by the enthusiasm for Physics that our Yr 12 demonstrated and that made her wonder why her students don’t show the same enthusiasm in her lessons!

We also invited some special guests to our first play:

-          Tina Crimp (Partnership Manager, Techniquest, Cardiff) commented that the show was highly engaging and that the audience obviously understood the Physics presented to them and was also impressed by the confidence our yr 12 pupils showed.

-          Rod Cunningham (Science Advisor, Torfaen LEA) was impressed by the show and found it to be the type of stimulus that both A-level and younger students need to be motivated to study Physics at A-level and above, and this is in line to one of the Welsh Assembly objectives.

-          Paul Griffiths (Newport University) was also impressed by the interactivity of the play and by the interest and engagement shown by the audience.

The gift we presented to schools was well received and appreciated and it will be a good asset to the teaching and learning of the Physics topics we demonstrated in our play. The idea of the play and of the gift was also to spread the highly effective and visual demonstrations our pupils performed in the community around our school. We believe our play was not just for pupils in yr 9, but also for the teachers that accompanied those pupils, as they could see how much Physics can be explained using our device and also use the same modulated laser pen we gave them as a gift the next day to do similar demonstrations with their own classes. So, our project has a strong component for the professional development of colleagues too. And this last point was demonstrated by what happened after our performances and as our project built momentum!

Building Momentum (October 2008 to February 2009)

IoP Welsh Conference for Physics Teachers

Our project picked up momentum very quickly, probably thanks to some of the guest that observed our progress. In fact, in October we were invited by the Institute of Physics to run a workshop at the Brecon 7th Welsh National Conference for Physics Teachers on the 8th October 2008. In this workshop the Institute of Physics funded the equipment for building one set of our modulated laser pen for each of the attending teachers. We took with us few pupils from the play and they could not just explain how they used the device to put up a show, but when the teachers were building their own sets they would go around and help in some of the trickiest bits. It was very exciting to see pupils becoming Instructors to teachers and again this developed our pupils’ confidence and team work skills even further!

With this workshop our project has, therefore, reached beyond our LEA in Torfaen and Newport into various parts of Wales. Well, actually there were teachers from outside Wales too, as far as Southampton.

Gary Williams (IoP Physics Education National Coordinator) was well pleased with our workshop and praised particularly the fact that individual teachers were making their own sets and enjoyed the hands on nature of the workshop.

Mike Pickin (Senior Lecturer in Science Education, UWIC) also attended the workshop and believed our project is having a great influence in Wales as most of his student teachers were also attending and they will have the opportunity to use and disseminate our project in various schools around (at least) South Wales, although some might even find employment in England. Also, he thought the idea of the play to be brilliant and just the kind of project that would motivate young people like his daughter (who’s currently in yr 11) to take Physics at A-level.

The outcomes of the workshop were so good, that the IoP asked us to repeat the workshop in a Twilight session in our school and in St Cyres School in Penarth (south east of Cardiff) for teachers in South Wales. The latter took place on 26th February 2009.

ASE Meeting (Techniquest, Cardiff)

We were also asked to speak about our Rolls-Royce Science Prize project at the ASE meeting in Techniquest (Cardiff)on Thursday 29th January 2009, where we took some pupils to perform the prelude to the play and explained how our device works.

Stretching the students (March 2009)

There is no doubt that our play was perceived as being highly engaging for our audiences, but it also had components that stretched the yr 9 pupils well beyond their normal programme of studies. In fact, the explanation of the Photoelectric Effect is part of the A-level Specifications and not GCSE, so a good part of the pupils we addressed will not carry on studying the effect, as they will either leave school, or maybe not take up A-level Physics, but they will at least have had some experience of A-level Physics, explained in ways accessible to them, that would make a memorable mark in their education. Also, for those that will choose to study Physics at A-level, demonstrations such as these might help them making that choice and becoming motivated to pursue a career in a Physics related job!

However, we felt the need to stretch our yr 12 pupils to Degree level too. We soon realised that they could understand easily how their modulating circuit and receiver worked, but that they didn’t really have much understanding of how a laser diode actually achieves emission of light. Also, although this was a topic that interested our pupils, we did not have the expertise to explain that device appropriately to them. So, we approached Cardiff University and asked if they could organise a lecture on laser diodes for our students. It turned out that Cardiff University is one of the leading centres for the development of new laser diode devices and they have a lab where they produce their own laser diodes. Professor Blood was happy to invite our pupils and talk to them about such devices and our yr 12 had the opportunity to observe the production of the lasers in the lab. This was quite stimulating for them, as they could see how a real lab operates and they could see that you don’t need to be superhuman to get into Physics research, but that University labs are populated by normal postgraduate students like they could become in few years time.

We have a legacy (April 2009 onwards)