Physics Coursework

[DSA]

Hi,

 

Just wondered if any of you have any ideas for a title of my latest physics coursework.

 

We have to write a project on ANYTHING we like physics related, as long as it is A-level standard physics. What a great title!

 

I was wondering if you could think of any interesting things to look at in the technical industry, so to speak - either lighting or sound, or indeed television I suppose.

 

It just needs to be specific and have a lot of obtainable info for research on the topic, eg photos, data, samples etc.

 

Final project is meant to be 2000-4000 words.

 

Thanks for help,

David

[Brian]

Just how difficult is A-level physics? Give us an idea of what you've covered.

[Angelic]

Do some cool stuff (no pun intended ;) ) about low lying fog and the various methods used to create it - I seem to remember that being popular when I was at school (admittedly a while ago!).

[gareth]

What about dichroic filter technology? Or discharge lamp technology?

 

The thing I remember most about A-level physics is one or other of the class members occasionally writing "Steve Evans is a shortarse" right at the top of the whiteboard, meaning that our 5-foot-nothing physics teacher would either have to stand on a chair to wipe it off, or leave it there for the whole lesson. ;)

[Angelic]

;) :** laughs out loud **: :** laughs out loud **:

 

Dichroic filter technology - that sounds good!

[peter]

I wrote mine (last year) on LED Lighting compared to the historic lighting, explaining the basic physics behind gas lights, tungsten halogen, discharge, colour mixing and then moving on to LEDs and their limitations. Got an A, so I must have done something right. Contact me by PM if you want to take a look... purely for research purposes though!

[DSA]

Well, it covers quite a lot really - not GCSE if that helps.

 

Effectively nothing so simple that a year seven would understand it second time, and not too difficult that Einstein couldnt figure it out.

 

Really anything which is interesting and not too simple to understand, and also is not tooooooo broad a subject, for obvious reasons.

 

For example we cover imaging, sensors (well electronics really), communication, materials, quantum physics, waves (eg standing, superposition etc) and simple mechanics at AS, and for A2 we have covered gravitational laws, 'simple' cosmology, gas laws, and capacitors/radioactivity.

 

If anyone is interested we are following the 'Advancing Physics' syllabus - Advancing Physics. The syllabus is all on there.

 

HTH

David

[Ben...]

Well, if you like mechanics you could analyse your lighting grid and work out how likely it is to fall down - or just how dangerous tallescopes really are (see this thread for some inspiration ;) )

 

Otherwise, like Peter suggests, a decent comparative analysis of LED lights vs. filaments would be interesting - things like comparing the sharpness of the beam, how it falls off with distance, even-ness, colour temperature, lifetime, useage cost etc.

 

And there's a suprising amount of physics in gels - making something that selectively absorbs certain wavelengths of light will involve some pretty hairy quantum physics if you look closely at it. And if you include looking into colour temperature of tungsten bulbs you get into black-body radiation, and more quantum mysteries.

 

Alternatively you could try and explain the history of dimming - scary reactant dimmers, triacs and modern digital thingies (which I have no idea about.)

 

And with sound systems you could look into what decibels are actually on about, find out why a 100W system is only twice as loud as a 10W system, and explain why turning the volume all the way up on even a well designed sound system will cause distortion - although that is more electronics stuff. More physics-y would be explaining balanced audio, why it's needed, and how it works, which easily drags in various bits of electromagnetism. Microphones also take advantage of various different electrical effects which a lot of people don't really understand.

 

If you're feeling exceptionally brave you could look at how the output from speakers interacts with the shape of the room they're in, but that's a "non-trivial" problem :** laughs out loud **:

 

I should add I've only recently survived a physics degree and my memory of what A-level covers is a bit fuzzy, so if you want me to elaborate on any of that lot feel free to ask.

[Brian]

looking at what your course covers I'd definately go down the dichroic filter and/or new light source route. How about a lamp that you can change the colour of at source so you don't need gel (not 3 LEDs in a cluster, a single 'lamp')? Or more efficient sources (again not LED).

[Tomo]

Alternatively you could try and explain the history of dimming - scary reactant dimmers, triacs and modern digital thingies (which I have no idea about.)

"Modern digital thingies" aren't much different to Triacs actually - they're (usually) a set of electronically-triggered thyristors cutting out part of the sinewave, and a triac is - you've guessed it - a pair of thyristors that cuts out part of the sinewave.

 

The clever bit is choosing when to switch - old triac dimmers used a potential divider to trigger the correctly-biased thyristor in the triac at the 'right' place, and modern dimmers use a set of sensing electronics to monitor the incoming waveform and trigger the thyristors correctly.

A very similar circuit (add a capacitor and an inductor) is used in switch-mode power supplies (AC to DC converters) and inverters (DC to AC).

 

The other system that can be used is a set of MOSFETs, but I don't believe them to be common as the circuitry required to protect them from stupid users and power surges is much more complicated. Plus they are really for DC to DC conversion, and tend to be lower current rating.

- It's possible to get thyristors (often known as Switched Current Rectifiers (SCRs)) rated for mega-amps at thousands of volts!

They're expensive, but imagine a dimmer pack that can supply over a gigawatt per channel...

 

I've got loads of notes on the darn things - the joys of power electronics!