Showing posts with label physics. Show all posts
Showing posts with label physics. Show all posts

Saturday, 31 May 2014

The Changes to Physics NC 1999 to 2014

Electricity and Magnetism 



I think that the new national curriculum does show an increased ambition for students. 

There is specific reference to potential difference and resistance as well as V=IR in the new curriculum. However, I imagine that most schools are similar to the ones I have worked in and teach potential difference as part of key stage 3, and the concept of resistance as something that opposes the current flowing. The extra activity will involve the students calculating resistance. We have fixed resistors with small values, that will be useful for this type of activity. 

Static electricity is new, but I don't think that this will take a lot of time to teach. Students are familiar with static electricity and the national curriculum doesn't expect them to understand earthing as a concept. If students have studied magnetism previously then the idea of 'opposites attract' should sit comfortably. They may also be aware of electrons as a concept from current electricity, if this has been introduced. 

Magnetism has been increased to include compasses, but these are usually part of schemes anyway, so won't be a departure. Including the motor as an application of electromagnetism is a bit different and will require adaptation of resources, but I don't believe that it will require more of a challenge than teaching the door bell or speaker. 

Forces and Motion




Looking at each section in turn, using the speed = distance / time equation isn't new, although distance-time graphs seem to be, they are currently taught at key stage 3. The new section seems to be relative motion. 

In the forces section, there aren't many areas that are not currently taught, except perhaps work done and energy changes on deformation. I am interested to know what this should look like, and whether it should be approached in the forces topic, energy topic or both.

We already teach Hooke's Law in Year 7, but it is more about developing the ability to draw a line of best fit and interpolate from a graph than about recognising when a material obeys Hooke's Law. Air resistance is taught in Year 9. Most schemes of work I have taught have also covered the difference between contact and non-contact forces, so schools may already have resources to cover these curriculum points. 

Pressure in liquids is not explicit in the 1999 curriculum, but this is taught in schools, so again should not be a stretch to develop lessons for.

Waves




The obvious addition is the mention of waves in water. As we use water waves to teach about light, I can see that this can be added into light topics. In the QCA schemes light came before sound, but teaching sound first, then light and water and finally being able to compare the three would be useful. That water waves are light light and transverse, but also like sound in that they need a medium to travel in. 

I have never taught the pin hole camera before (although I have made and used a 'real' one in an extra curricular activity run by one of the technology teachers), it is part of some schemes however. 

The human eye is something that I have not taught at key stage 3 before. As I write this I am wondering what level of detail I will go into about how the eye works; will I mention long and short sightedness for example?

The word frequency appears in the new national curriculum. I don't usually ensure that students understand that different colours have different frequencies. I think this is because I don't usually teach light as a wave, I teach more about the properties of light and what it does. Teaching that light is a wave introduces some new questions for the learner - what is it that is vibrating? Light doesn't wiggle, it is a straight line.  

Space Physics



This is the area where information seems to have been stripped out. Satellites haven't been included. 

Although the seasons and day length were not included in 1999, but were taught in the QCA schemes, and I also think I have seen SATs questions about day length and the movement of of the sun across the sky. I note that the planets are not explicit in either curriculum. 

Energy





Energy is the bit that needs work. I am not entirely sure how I will include 'simple machines'. Physics for you will help, I hope. I am also undecided of how to approach kWh as a unit of energy. 

The issue with physics is that we need to teach transfer instead of teaching transformation. Reading work by Robin Millar is a good place to start. e.g. http://www.york.ac.uk/media/educationalstudies/documents/research/Paper11Teachingaboutenergy.pdf  and http://esummit-msu.net/users/robin-millar

Teaching food energy, energy resources, and heating and cooling is something covered in previous schemes of work. It is interesting that convection is not explicit in the new national curriculum. I think that it is something worth teaching to recap the idea of density and prepare students for GCSE, where it will be necessary to help understanding of how insulation works. 

Power is an interesting addition. I know the OUP scheme from the early 2000s covered it, so there are resources available. 

Matter

The new addition is the reference to matter. 



It will be interesting to see the ways that schools and publishers approach this. I would prefer to teach the particle model in Year 7 chemistry and then use physics contexts to revisit the ideas. In that way we will cover the concepts written in the national curriculum, without needing to add another topic that recaps the ideas already taught in chemistry. 

For example, Brownian motion will be taught in air pressure, change of state will be taught as part of the heat energy topic as well as the changes to the spacing of particles as temperature changes. Density will be taught in floating and sinking, etc etc. 

Hopefully these observations will help someone. I will try and do the same things for biology and chemistry. 

Sunday, 10 March 2013

Festival of Physics

I believe that you need three things to be a good science teacher. 1. An understanding of the place of science in the curriculum, 2. An understanding of how children learn and 3. A passion for science for the sake of science. This blog post is about number 3.

When I first started teaching I had come straight from my degree course and to be honest I was "scienced-out". Over the years that has changed a lot. As my degree level knowledge has wained my love of science for the sake of it has increased. So I gathered together my family (partner -48 and step-daughter -12) on saturday and headed to At-Bristol for the IoP-South West Branch Festival of Physics. We saw lectures about colour perception, Astronomy, Molecular Gastronomy and a workshop on the Hydraulics of helicopters.

All three of us had an engaging day; we learned something new from all of the lectures.

The day started with a lecture about colour. It took our key stage 3 knowledge on light a step further. My step-daughter who recently studied light in year 8 was able to happily access the ideas being talked about. The lecturer covered colour addition and subtraction and proved that what we teach at key stage 3 isn't quite the full story.

The lecture about the Universe was nothing that we don't teach at GCSE. However she included information about the astronomers that helped make the discoveries - I didn't realise so many were women! The presenter also talked about amateur astronomy, and showed us some amazing images she had taken, explaining the equipment she used.

The hydraulic workshop was excellent. The presenter works for a company that makes helicopters and despite the high technology involved was able to explain the ideas behind moving the angles of the propellers in terms of year 9 pressure. The teachers in the room (there were 5 of us) were all excited by his equipment and took a lot of photographs to recreate the equipment at school!

The last lecture was about molecular gastronomy. We were shown the RSC video of Heston Blumenthal eating tobacco jelly. Again linking to the curriculum. It was interesting to find out how much your own experiences affect the taste of the food you eat.

I am always impressed that my GCSE and Key Stage 3 science knowledge is enough for me to access a lot of the general interest science lectures and TV programmes. Of course I also have some knowledge of A-level Biology and Chemistry from 15 years ago, and my key stage 3/gcse knowledge is very strong due to 10 years of teaching it!

More than that though, by attending events like this I can relate the work of real scientists to what I teach. It is relevant that students understand about colour addition and subtraction in year 8 if they are to be involved in the digital arts. If cooks and chefs understand that people enjoy food more if it is served off a white plate that will help their business be more successful. I now have some information about how to be an amateur astronomer and may encourage one of my students to get involved in this. Knowing that helicopters use hydraulics may help to engage a disaffected student.

Well done to the IoP south west branch. I am already looking forward to next year!


Saturday, 23 June 2012

What is Refractive Index?

The first lecture during the South West Physics Teacher Conference was entitled "Warping Electromagnetic Space: The Quest for Invisibility" by Dr Alastair Hibbins from the University of Exeter.

Dr Hibbins is part of a team trying to build metamaterials that will hide objects or make them more visible. To do that he has to use elements on the surface of materials to alter the refractive index.

What is the refractive index?

When I teach this at secondary school I just teach that light slows down in a different medium, and this is what causes the wavelength to change. There is a complicated proof involving drawing a diagram with lots of lines and comparing angles using trigonometry that generates snells law.

The idea that waves just slow down has never sat well with me. I haven't considered what really causes the effect of refraction; I didn't study this at university.

Dr Hibbins described refraction as the change in phase speed of the wave cause by the electrons in the medium being forced to vibrate by the incoming electromagnetic wave. A vibrating electron generates another electromagnetic wave, which is out of phase to the incoming wave, these two superimpose and give a wave with a shorter wavelength.

This would explain why different frequencies have different refractive indexes.

Something else that I had not considered is that you can prove snell's law using momentum as well as differentiation and how I would normally demonstrate it via trigonometry.


Wednesday, 13 June 2012

Why don't as many girls study science and in particular physics as boys?

I read with interest a letter in the June 2012 edition of School Science Review about the topic of addressing the lack of girls in physics.

Do girls dislike physics because we don't teach a curriculum that appeals enough to them? Should physics include more references to the way that it can help people and be less about nuclear bombs?

I would agree in my experience girls do find physics less relevant to them and their lives. The context of the forces module in OCR Gateway is transport; we often use firing guns as an example of momentum. Is it fair to constantly link physics with these more traditional applications? What are the alternatives?

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