Leaving Cert Physics: Derivations

There are a total of 11 derivations on the Leaving Cert Physics syllabus:

1. Three equations of motion

2. F = ma

3. v = r w

4. Relationship between Periodic Time and Radius for a Satellite in Orbit

5. To show that any object that obeys Hooke’s Law will also execute SHM

6. Equation for a diffraction grating

7. Resistors in series and in parallel

8. F = Bqv

I have put the derivations together in a single word document, together with the year in which they have appeared on an exam paper.

It can be found on the revision page of thephysicsteacher.ie

Hope it proves useful

Survey finds Physics dropped in 10% of schools

With all the media attention on NAMA these times it’s understandable that most of us missed this headline from RTE the other day (hat-tip to eagle-eyed Jude for bringing it to my attention).
The RTE article leads with the following:

Research suggests that almost 10% of second level schools have been forced to drop Physics as a subject offered to students.
The findings indicate that the decision is as a direct result of education cutbacks.

Not a happy statistic, but presumably many of these schools had less than ten students in the class, and it just wasn’t feasable to maintain this. So why don’t more students do physics? It’s a very complex issue but the problem is causing concern to authorities throughout the western world. I believe that one very important factor is the picture of physics which students get from the  Junior Cert – if we don’t get this right then it’s going to create a poor impression when they go to choose their leaving cert subjects.

So what would I change in Junior Cert Physics? – stay tuned.

btw – should we read anything into the fact that the accompanying picture in the RTE webpage is chemistry-related, not physics?

Another Physics teacher shares resources on Youtube

Tom Healy teaches Physics in Cabinteely Community School and for quite a while now has been uploading revision videos on Leaving Cert Physics to youtube. He has almost 50 up there by now and has divided them into Mandatory and Non-mandatory experiments.

A wonderful way to revise, but also a wonderful resource for any new teachers.
Why couldn’t this have been available when I was starting out?

I posted very few videos on youtube last year, and am determined to rectify that this year, and in particular to put up some clips of Junior Cert classes.

Here are a couple on spherical mirrors:

The mirrors in this next one were purchased from educationalinnovations for about €20. They have a larger, 22 inch version for \$1,195. Just a little out of our budget.

The Photoelectric Effect

I have been trying to get this to work for years, without success. And then recently I tried it again and lo and behold it worked like a dream!
Part of the problem was that if the day was even slightly humid the gold leaf electroscope wouldn’t hold its charge.
Secondly it had to be charged negatively, and I was never sure if I was charging it positively or negatively.
Thirdly I didn’t realise that I had to sandpaper the zinc in advance to remove the oxide layer.
Fourtly I don’t keep a list of questions related to demonstrations which I can’t get to work, so I only remember that there is a problem when I go to teach it each year, instead of asking an expert.

And I apologise for stating that this is “the most important least impressive experiment in the history of science”. It is actually rather impressive.
If I do say so myself.