You’re on your own today team but I have every confidence in you. Work together, listen to each other (everyone has worthwhile contributions), be curious and persistent.

1. Read through all the instructions before you do anything
2. Read p29 – 32 in your text. Pay special attention to fig 2.10 – 2.12. It may also be helpful to check out the  corresponding section in the chapter summary. (5 minutes – quite time)
3. Discuss any questions you have with the whole group so you reach a shared understanding. If further research or reading is required do it (5 – 15 minutes)
4. Design a short investigation that could be conducted in the Slater building lift based on the principles you have just talked about. “What can you determine about the motion of the lift?” Don’t forget to identify what data will be recorded, when and how. I strongly recommend taking a camera phone (or similar) to capture the essentials of what you do.
5. Get the scales, go over to the Slater building and gather your data. An X1 key will be required to operate the lift (teacher should have this)
6. Put some of your observations in the comment section below
7. Try Q17 p34 in your text book. We’ll check it on Friday

I will try to get an AudioBoo up for you by tomorrow morning explaining “Apparent weight” in my words. (It may or may not be helpful…)

I am a Hyperphysics tragic and it’s more than worth your while learning to navigate around the site but because I am super nice I’m providing a direct link to the projectile motion section. (I know, I know please don’t send gifts)
Now I can’t give you a Hyperphysics link without also giving a shout out to one of the locals. University of NSW School of Physics have put together a fantastic bunch of stuff titled Physclips. It’s not as comprehensive as Hyperphysics (mechanics, waves, electricity and magnetism only) but the multimedia content and Australian accent evens up the score I feel.
Opinions welcome.

First day back.
So how much do you remember?
We’ll check out how the “trip to Hilary’s” went to start with and take it from there.
Let the games begin!

Pleasing to see that some of you are accessing the resources. Don’t hesitate to leave a comment, ask a question or make a suggestion.
I promised to post some of the links used in class the other day. Remember they are all accessible from my delicious feed although you will have to put in some key words to narrow it down.
We looked at this one from University of Toronto showing the displacement, velocity and acceleration time graphs for a body undergoing constant acceleration along with the algebraic derivation.
Here’s another from UNSW which is part of their PhysClips project. This one goes a step further with a video explanation, background information and further content. Like the PhET site this one will get a good workout as the year goes on.
Complete “Trip to Hilary’s” as best you can using the information on the sites as a guide. Scan or photograph your work and email in and I can give you feedback.

Above is a quick (and interesting?) summary of what we talked about today.

Here are some links that may help with your understanding of

forces

Forces in 1 dimension from Physics Education Technology at the University of Colorado at Boulder (you will need Java installed on your machine, there are instructions on the site)

and vectors

Resultant of forces from Walter Fendt’s excellent collection

Adding 2 Vectors from the University of Toronto Department of Physics site

RH Grip Rule

Originally uploaded by coach_robbo

I’m slowly adding to the concept maps to my Flickr page to include some of the things discussed in class. Visual thinking tools have been shown to improve understanding of complex topics.
Let me know if there are any requests.

photoelectric effect current and voltage
Originally uploaded by coach_robbo

Here is the photocurrent vs voltage graph we concentrated on for a bit today. Add this to the energy vs frequency graph and you have the photoelectric effect pretty much covered. If you follow through the flow chart in the earlier post “Photoelectric effect starter” you should see consistency with both graphs. I cannot recommend enough reinforcing this with the PhET photoelectric simulation. It’s available for download so you can run it offline if preferred. (You will need to install Java but there are instructions on the site.) Do it. If you invest 20 focused minutes (not “Oh, I’ll just listen to this and watch that at the same time” – focused minutes) it will pay you back.

photoelectric effect energy vs freq
Originally uploaded by coach_robbo

Listen to some terms and definitions associated with the photoelectric cell and the photoelectric effect (along with special comments). You simply have to know what these things mean. See the “audio bites” if you prefer a more polished version. The standard energy vs frequency graph you would expect to see goes with the audio of terms and definitions and has points of interest labeled.

The photoelectric effect is one of the more trippy spin outs that nature can throw you IMHO. I mean if you think about it, it doesn’t make much sense. Well this is where the simulations can really help. The very best one is the Photoelectric Interactive Solution (PhET) from the University of Boulder (we love those guys!) It shows the electrons being ejected from the photocathode and moving from one plate to the other. This visual is usually very helpful in developing understanding of the principle and the photoelectric cell. Current vs intensity, current vs voltage and electron energy vs frequency can also be viewed. Grab the virtual experiment instructions from here and see how much you can work through.
Walter Fendt has an applet offering similar features but nowhere near as “attractive” with it’s presentation. Repetition with variety is the key. We will play some real equipment next time we meet in the laboratory to take a closer look at the photoelectric effect.

Light is predominantly thought of as a wave these days but this was not always the case. Our old friend Isaac Newton put his significant scientific weight behind the particle (or corpuscular) explanation for much of light’s behaviour. It was up to guys like Young, Huygens and Fresnel to challenge the old views which was published successfully by Young in the very early 1800’s. The double slit interference experiment that underpinned the “light as a wave” model is often referred to as Young’s double slit experiment.
There is a nicely done, full colour online simulation of the double slit interference experiment here that is well worth exploring. The width of the slits, slit to screen distance and frequency of light are all adjustable and the representation of the wave from each slit along with their superposition is extremely helpful for an understanding of path difference. Quantitative data is available if desired. Walter Fendt treats it in a more simplified way here.
If that is a bit much or a refresher is required review your knowledge of waves at the ScienceJoyWagon. Some simulations require a membership but the ones available for free viewing will still prove useful.
Walter Fendt has a brilliant simulation of reflection and refraction combining the ray model with Huygens’ wave front principle. Highly recommended