BlogPhysicsThe Ultimate Guide to Year 11 Physics Module 3: Waves and Thermodynamics

# The Ultimate Guide to Year 11 Physics Module 3: Waves and Thermodynamics

Just started Year 11 Physics Module 3: Waves and Thermodynamics and feeling a bit lost?

Don’t worry! Our comprehensive guide to Module 3 will help you warm up to the new syllabus!

In this article, we’ll cover what exactly Module 3 is all about how to prepare, use class time and smash through Module 3 on the journey towards your Band 6!

So, what are you waiting for? Let’s dive in!

## What is Module 3: Waves and Thermodynamics all about?

So, what exactly is involved with waves??

Get ready to be disturbed

Waves happen when systems get bumped out of their happy, relaxed equilibrium state (i.e. when energy inputs need to get spread around).

Think about this little duck disturbing the peace and quacking:

This scene could not be wavier.

Light waves (arriving from a big disturbance out in space), first bounced off the buildings, then off the water surface and into a camera to make data. Your PC screen is turning that data back in to light waves, so you can see the picture (with the 2 light wave detectors on your face).

The duck flapping about and quacking starts up the water waving, as well as all the air in the vicinity (you have 2 sound wave detectors on your head).

Along every arc of this story, waves were spreading energy out. That’s what waves do.

In fact, whenever the Universe is doing something and spills some energy, this drive to spread it as far out as possible is explained by thermodynamics!

## Breakdown of the Module 3 Inquiry Questions

You’ll be interrogating all the details of wave behaviour, including:

1. The things that happen when different types of materials start waving.

2. The things that happen when waves come together at the same spot

#### Inquiry question 1: What are the properties of all waves and wave motion?

(i.e. How do I describe waves?)

Physics operates in the hidden common ground between seemingly different phenomena: How are all these different types of waves the same?

You’ll be looking at the way that they all ripple energy out without re-locating matter (lucky for us that when something makes a noise, all the air doesn’t end up over there!)

Whether it’s a violin string, light, air, water, earthquake, recently discovered gravity waves -or whatever is doing the waving- they all have these common features:

Velocity

Frequency

Period

Wavelength

Displacement and amplitude

And you’ll do experiments to measure these general descriptions of waviness.

#### Inquiry question 2: How do waves behave?

(i.e. What do waves do?)

If Physics is worth its salt, we somehow must get from “light is something waving” to an explanation of rainbows; and “sound is something waving” to “how can I hear a loudspeaker from around the corner?

This one’s all about:

Reflection

Refraction

Diffraction

Wave superposition

As always in Physics, starting with simple truths and building upwards and outwards and filling out all the ramifications.

#### Inquiry question 3: What evidence suggests that sound is a mechanical wave?

Again, if Physics is worth anything, we somehow must get from “sound is something waving” to why F♯ sounds different on a guitar string and a piano string. Or for that matter, how things like “pitch” and “loudness” come out of “something is waving” at all!

You’ll do a bunch of fun experiments here.

#### Inquiry question 4: What properties can be demonstrated when using the ray model of light?

Why does the bottom of a pool look closer than it really is? Why is your reflection in a spoon upside down?

This last inquiry question provides a great background for “The Nature of Light” next year!

### What about Thermodynamics?

#### Inquiry question: How are temperature, thermal energy and particle motion related?

Thermodynamics is, at its heart, the story of how bulk communities of molecules (more commonly referred to as “all the material around you”) pass energy between each other.

It’s, in a sense, energy economics:

The question:

If I let 25 million Australians go about their daily processes, transferring money hand-to-hand, how does the total \$1.3 trillion dollars in the economy end up looking spread out?

Has a mind-blowingly similar answer to:

If I let a trillion trillion water molecules bump around swapping parcels of energy between each other, how does the total energy end up looking spread out?

“Temperature” is something like “average wealth”: It paints an idea of what’s going on from afar (after all, we can’t see atoms from up here), but where it comes from is ultimately the individual stories in concert.

So, in thermodynamics you’ll do a lot of bridging between the atomic world and the human scale where we boil water to see what happens!

If you’re also doing Chemistry, you’ll enjoy some massive overlap here.

## How to get a Band 6 in Year 11 Physics: Waves and Thermodynamics

Here’s what Waves begs you to master:

1. Describe waving in its details (how extreme is the waving? How frequent?).
2. Describe phenomena borne out of travelling waves (things like bending light, the harmonics on a guitar string)

Thermodynamics begs you to master:

1. How zooming out from jostling particle populations gives average measurements on our level (i.e. temperature, when energy inputs are spread around)
2. Methods of heat flow between bulk materials in contact

### Step 1: Watch the experiments you will have to conduct before class.

Abstractions like force vectors are gone for now.

You can literally SEE a lot of this module in action. Watch things like plucked guitar strings in slow motion, and you’ll develop a better intuition before formally learning wave behaviour in class.

##### The first dot point in sound is:

conduct a practical investigation to relate the pitch and loudness of a sound to its wave characteristics

This is the sort of thing that begs Physicists to make demonstration videos… (I searched for “sound waves demonstration”). There are so many amazing, clear demonstrations from Universities and teachers to science shows and backyard science YouTubers.

##### Such as this one on refraction and total internal reflection of light waves:

Just passively googling “why does light bend through glass” in your chilled non-study time, after watching one of those videos weeks ahead of your own experiment can be a great way to teach your brain to think about Physics naturally.

Plus you’ll know what to look for when you’re doing the experiment yourself!

### Step 2: Constantly shift between micro and macro world-views.

Research in education shows that the key to unlocking understanding in this area is being able to seamlessly switch between the zoomed-out and the zoomed-in; like being fluent in two languages and saying the same thing in each one.

Once the behaviour of the bulk (from our view of things all the way up here: the temperature, pressure, volume that we measure) seems interchangeable with descriptions of how the many individual particles are organised; then things are really clicking in place!

If you’re thinking about any thermal phenomena at all on the macro-level, STOP and:

1. Visualise what the individual atoms are doing in your head, then:
2. Diagram their motion and make little descriptions to the side.
3. Write a short, written explanation of how the situation observed up here (e.g. something is colder, higher pressure, cooling down) arises when averaging over how the trillions of trillions of particles are jostling around.

(Imagine you had to explain to an atom what “heat transfer” means. How would you do it without saying things like “feels hotter”)

Imagination becomes quite important in Physics, particularly in Year 11 HSC Physics: Waves and Thermodynamics.

Here’s the great physicist Richard Feynman describing “hot” and “cold” in chemical reactions:

### Step 3: Visualise, visualise, visualise!

This whole business of things waving to-and-fro and molecules bashing around handing energy around to each other is great for engaging your visual imagination to help in grasping ideas (which are often only spoken to you, or written down in books).

Sometimes seeing something come to life engages your brain in a new way!

Jump on places like these, which are packed with interactive simulations and animations of the concepts you’re learning:

#### Step 4: Recast the role of class-time in your life

Because the syllabus is more internationally aligned, there are riches of resources out there already, beyond your prescribed text, that can be used to throw yourself into the content ahead of your class.

#### The University of Sydney has a great summary:

This recasts your class time in the role of a revision session with an expert consultant (teacher), ready to answer your pre-formed questions.

## In summary, how can I best prepare for the Year 11 Physics Waves and Thermodynamics module?

#### Step 1: Seek out video of the real-life experiments and watch others doing them before you do!

This is great because there’s just so many videos of people interfering light together, bending laser beams and showing sound waves in ultra-slow motion. Reading about waves just doesn’t do it justice!

In this way, you’ll develop an intuition for wave motion and know what interesting things to look for when you do the practical in class; and you’ll already have burning questions formulated (and will remember the explanations well for this reason!)

#### Step 2: Keep translating between the atomic level and the human level, when learning thermodynamics.

Always keep in mind that everything you observe around you is the zoomed-out, averaged-out results of trillions of trillions of assembled particles.

Convince yourself what each individual pixel is doing at a given time on your TV screen is equivalent to describing the overall image from afar!

Male notes on experimental observables like temperature and heat flow and make sure you could explain them to an atom who’s never seen the world as zoomed out as you have!

#### Step 3: Visualise!

Don’t settle for textbook descriptions anymore. Especially now that we’re talking about things waving back and forth and the dynamic bustle of jiggling subatomic particles!

If a concept emerges as a sticking point for you, seek out a visualisation that turns it to life!

#### Step 4: Re-cast the role of class time in your life

Don’t make class time your primary learning ground anymore. Make it a revision session that you bring questions to; your teacher becomes your consultant/mentor for mastering the subject and in this way, you really own this two-year project!

## Are you looking for some extra help with Waves and Thermodynamics?

#### We pride ourselves on our inspirational Year 11 Physics coaches and mentors for Waves and Thermodynamics!

We offer tutoring and mentoring for Years K-12 in a large variety of subjects, with personalised lessons conducted one-on-one in your home or at our state of the art campus in Hornsby!

To find out more and get started with an inspirational tutor and mentor get in touch today!

Give us a ring on 1300 267 888, email us at [email protected] or check us out on Facebook!

Adrian Wendeborn is a qualified Science and Maths teacher with a Physics/Chemistry double-major degree from USYD and a GDipEd from UQ. Adrian has taught in QLD and NSW and has worked with Art of Smart Education as a campus teacher, tutor, resource developer and Head of Faculty.

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