Archive for April 2012

Time to study Relativity (updated x2)

April 29, 2012

Well, after our EPI, it’s time.

Time to get back relativity – but that does bring up the sticky issue of time itself. Time should be the most reliable thing in the universe; after all it is absolute, right? I mean aside from the jokes (like the one on the left), time is defined by how long it takes to complete a task, and that can’t be changed by how fast you are going – can it?

Well, like many questions about this level of physics, the answer is Yes, but No. It doesn’t matter how fast you are travelling, everything takes the same amount of time it normally would… from your point of view.

Ah, it’s those never-to-be-sufficiently-cursed frames of reference again.

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Genetically modified lizard and alligator invades on year 10 science class. Who will survive?

April 23, 2012

For all the news and updates of genetic information and natural selection this is a must read!

This post is an evolutional changing experience, taking you from the basic building blocks of life through to inheritance then through to natural selection of monsters vs students? Who will survive?

The monster was last seen in the classroom and reports of finding eggs are still flooding the phone lines with sighting of the monster and monster egg being discovered. Let’s hope for the human race all eggs have been found and destroyed.

The monster is still at large and numerous sighing have been reported. Where it can be found no one knows, but one thing is for sure the environment it is in is suitable for the monster.

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Don’t make it an EPI(c) FAIL!

April 20, 2012

The extended practical investigation (EPI) is a real trial by fire – if you don’t prepare, you are going to get burned. The EPI is all about your ability to combine the physics theory you have learnt in class with the application to real world situations.

This combines your understanding with your ability to make measurements carefully and accurately, taking into account the amount of precision you are able to achieve with the tools you choose to use.

It is also a trial of your common sense – can you think through the scenario and make sensible decisions about what you can investigate, and how you will go about it in a timely manner.

There are four main parts of this project: Planning; Measuring; Analysing and Reporting. You will need to plan to do a lot of work outside of class and how to divide up the work with your partner – the in class times are not the time to be trying to decide what to do; you must be working diligently in every second you have available – you must know what you are going to do and get on with it. You do not have time to spend figuring out what you are going to do.

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Relativity – it’s all about knowing your place

April 11, 2012

Relativity, along with Quantum Physics are used as proxies for impossible to understand science; they can be used to justify almost anything (1, 2). By the end of this unit, you will have an introductory understanding of the concept of special relativity, and how it relates to our prior studies.

The basic concept of relativity is simple enough; the speed of light is constant and nothing may go faster than it. Not difficult, right? Well the usual example to explain why such a simple concept is problematic is a thought experiment: Imagine a car that could travel near the speed of light (I want one!), then you turn on the headlights. Won’t the light travelling out from the headlights go faster than the speed of light?

Yes? well then the speed of light isn’t a limit.

No? well then velocity vector addition doesn’t work.

Take your pick, but it seems like there are no good answers – either way things don’t seem to work way they should.

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It Fields Good!

April 11, 2012

Electricity is the defining feature of modern life; almost everything we do relies explicitly on control of electricity. Try to think of one thing that you do that does not rely on electricity, at least partially. Remember, that unless you are using candles, it is using electricity. Unless you walk there “in the altogether”, it uses electricity.

That’s all fine, but how many people actually understand electricity? Most people use it without a second thought – where it comes from, how it is made, and how it is controlled – yet freely express ideas that are, at the least, ill-informed, regarding electricity.

You will learn about electricity through this unit of study, from the beginnings, which is: Electric Charge.

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Up-celling yourself

April 6, 2012

We have nearly finished our studies into the structure of cells, including both animal and plant cells. We also have learned how to use a microscope, looking at onion skin cells (Here are some pictures if you are missing them: Unstained 100x, Unstained 400x, Stained 100x, Stained 400x.

We’ve also looked at the parts of the cell, including the simplified internal parts – such as the organelles like the mitochondria, nucleus, chloroplasts, vacuoles, endoplasmic reticulum (E.R) and ribosomes, and cell structures like the membrane, cytoplasm and cell wall. You have also worked on learning what these parts look like, and what they do (their functions). You (should!) have submitted a 3-D model and cell analogy, demonstrating both that you know what the parts look like and what they do – it is important that you know these concepts and terms, and that they appear in your glossary, because there will be a test coming up soon…

I’ve attached something to help you understand and remember the parts of the cell below the fold; you may be familiar with it…

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All Systems GO!

April 5, 2012

So, here we are at the end of term 1. A lot has been covered in class this term – we started with some scientific processes, but quickly moved into body systems and interactions between systems, and have now transferred over to things that affect the whole body (so far we’ve looked at E-M radiation). We have quite a bit to cover yet, but before we go on, let’s ensure that everyone is up to date.

Notice that I wrote that “A lot has been covered in class” and not “we have done a lot in class”.

That’s mainly because I haven’t seen much work from many of you – something that you need to address urgently, because from the first day of next term, students who have not completed the work will be required to attend half-lunch detentions and JWOP to finish that work.

Here is a list of the tasks that must be completed:

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To unlock cells – you need a key (updated!)

April 4, 2012

So, we are getting towards the end of our first unit of study – Genetics & Natural Selection. We’ve looked at the relationship between evolution & natural selection. To finish this unit of study, we need to understand how cells propagate – how one cell becomes more.

This process is called cell division, and there are two main types: Mitosis and Meiosis. But before we get too far into this topic, you may want to revise the important concepts of Genetics. Here is a post that covers the genetics topics – I strongly suggest you go back and read it (and watch the videos!) – not doing this will do bad things to your results…

So, back to the cell division topic – what do you have to know? The problem is is you look this topic up on the internet, you will find far more information than you need at year 10 – information about what the different phases are, what happens during each phase, a lot of details. You should try and learn this information if you plan on studying biology during VCE, but otherwise you only need to know the basics.

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Projectile motion is all about throwing up… (updated)

April 1, 2012

Because you’ll get sick of it!

So this is a bit of a revision post – it is apparent that we need to review the concepts behind projectile motion. So let’s start at the beginning.

Whenever an object is thrown within a gravitational field, it’s trajectory will curve in a parabolic path. This happens because the object is attracted towards the earth, so the vertical component of velocity changes. Remembering that velocity is a vector, this means that the direction and magnitude will change. Because the acceleration component due to gravity is the same direction as the vertical velocity, this means that only the magnitude of the vertical velocity will change.

Because there is no component of acceleration in the horizontal axis, the horizontal component of velocity will remain constant. When you recombine these two components, you can see how the overall direction of velocity changes. The direction will change over the entire flight until (if it remains aloft long enough, the velocity will become almost parallel with gravity).

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