Year 8 Energy Project

Macarthur Wind Farm – photo by Josh Gow

Over the next two weeks I would like you to research and produce a report on one of the following topics:

Sources of Electrical Energy – choose ONE of the following:

OR Alternative fuels for vehicles – choose one of the following:

  • Hydrogen
  • Hybrid
  • Biodiesel
  • Ethanol.

KNOW –  What do you already know about the topic?

WANT  – What do you want to know about the topic?

HOW – How are you going to find out more about your topic?

ACTION – What actions might result from your new learning?

QUESTIONS – What new questions might you have about the topic?

LEARN – What have you learnt about the topic?

Make sure you include HOW the source of energy or alternative vehicle works and the advantages and disadvantages it might have (at least three of each). What is preventing this technology from becoming more widespread? Please present your work as a poster, slideshow, video, or written report. You should include at least four sources of information (References) in a Bibliography. This work is due Thursday 12th June.

Simple Circuits

We have done several experiments over the past few weeks to learn more about how simple circuits work. You have created a circuit using just a battery, globe and two wires and then constructed your own switch to turn the globe on and off. You then constructed your own torch from two batteries, a globe, cardboard tube, wires, aluminium foil, drawing pins, paper clips and sticky tape. Many of you were able to operate your torch using just one hand – great work! Unfortunately, we were unable to create a circuit with enough voltage to allow a small LED globe to operate using lemons.

We then looked at series (one pathway for the current to flow) and parallel circuits (more than one pathway for the current to flow). We learnt about ammeters and voltmeters and how they are connected. An ammeter measures current in amperes and is connected in series. A voltmeter measures voltage in volts and is connected in parallel across the load (globe, buzzer or other device). Find out more about series and parallel circuits at BBC Bitesize. Ausgrid also has some good information about  series and parallel circuits.

There is an interesting article from ABC Science here: “In this universe, charge is everything” and here: “How electricity makes things work.”

Year 8’s are Electrifying!

Image Source

Learning Intention: Students will remember some of their experiences of electricity and be able to identify a

This week we are starting a new unit about Electricity. What do you know about electricity already? Most of you know what it feels like to get a shock from an electric fence and have felt a ‘static’ shock when opening a car door or getting off a trampoline. But what is it that you are feeling? We will demonstrate the use of a Van der Graaf generator in class.

The first task is to write a list from A to Z of the equipment that uses electricity to make it work. All these appliances use an electric current that flows from the source (a power station), through high voltage power lines, transformers, local power lines, to your home, into the appliance and back again. Any electrical appliance relies on a complete circuit of conductors that allows the flow of electrons. Those electrons are the negatively charged particles that are present outside all atoms, and in a coil of wire, with magnets, they can move.Find out more about electricity here:

Origin Energy – What is electricity?

Understanding Electricity from About.com

What is electricity? – YouTube video

Hearing and Sound Waves

Photograph taken by Josh Gow at the Macarthur Wind Farm

Last week we learnt how the human eye can only detect a narrow band within the electromagnetic spectrum – what we know as visible light. Higher frequency waves are known as ultraviolet waves, X-rays and gamma rays, while lower frequency wavelengths are known as infrared waves, micro-waves and radio waves.

In a similar way, our ears can only detect part of the sound spectrum. Sound is composed of frequency expressed as hertz (Hz) and pressure expressed as  decibels (dB). This site has a simple description of what sound waves look like. Why is understanding about how sound works important? A local example is the controversy surrounding the potential health impacts of the Macarthur Wind Farm.

Since the introduction of the Renewable Energy (Electricity) Act in 2000 and the Renewable Energy Target Scheme in 2009, wind farms have become more prominent in Victoria. However, this has not been without controversy as some people claim that wind turbines can adversely impact the health of individuals living in close proximity. Concerns focus on infrasound noise, electromagnetic interference, shadow flicker and blade glint produced by wind turbines. “Infrasound noise” or “low frequency noise” refers to sound waves inaudible to the human ear (although this varies between individuals). ‘Low frequency noise’ is the term used to describe sound energy in the region below about 200Hz. The rumble of thunder and the throb of a diesel engine are both examples of sounds with most of their energy in this low frequency range.

‘Infrasound’ is also often used to describe sound energy in the region below 20Hz. Almost all noise in the environment has components in this region although they are of such a low level that they are not significant. Noise which has most of its energy in the ‘infrasound’ range is only significant if it is at a very high level, far above normal environmental levels.

Wind Turbine Syndrome(“WTS”) is an alleged condition proposed by pediatrician Dr Nina Pierpoint. She cites a range of physical sensations and effects (including sleep disturbance, headache, tinnitus, ear pressure, vertigo, nausea, visual blurring, tachycardia, irritability, loss of concentration, lack of memory, panic attacks, internal pulsation, and quivering) reported by people living close to wind turbines. Dr Pierpont’s assertions are yet to be published in a peer-reviewed journal, and have been heavily criticised by acoustic specialists. This article by the Drum on ABC claims that “this phenomenon has disturbing hallmarks of mass hysteria or psychogenic illness being whipped up by interests groups connected with climate change denial interests, some of whom have personal financial interests in fossil fuels.”

From the Australian Government National Health and Medical Research Council report – “Wind Turbines and Health” (July, 2012)

  • ‘There is no reliable evidence that infrasounds below the hearing threshold produce physiological or psychological effects’ (Berglund & Lindvall 1995).
  • Infrasound associated with modern wind turbines is not a source which will result in noise levels which may be injurious to the health of a wind farm neighbour (DTI, 2006).
  • Findings clearly show that there is no peer-reviewed scientific evidence indicating that wind turbines have an adverse impact on human health (CanWEA, 2009).
  • Sound from wind turbines does not pose a risk of hearing loss or any other adverse health effects in humans. Subaudible, low frequency sounds and infrasound from wind turbines do not present a risk to human health (Colby, et al 2009).
  • The Chatham-Kent Public Health Unit (Ontario, Canada) reviewed the current literature regarding the known health impacts of wind turbines in order to make an evidence-based decision. Their report concluded that current evidence failed to demonstrate a health concern associated with wind turbines. ‘In summary, as long as the Ministry of Environment Guidelines for location criteria of wind farms are followed … there will be negligible adverse health impacts on Chatham-Kent citizens. Although opposition to wind farms on aesthetic grounds is a legitimate point of view, opposition to wind farms on the basis of potential adverse health consequences is not justified by the evidence’ (Chatham-Kent Public Health Unit, 2008).
  • Wind energy is associated with fewer health effects than other forms of traditional energy generation and in fact will have positive health benefits (WHO, 2004).
  • ‘There are, at present, very few published and scientifically-validated cases of an SACs of wind farm noise emission being problematic … the extent of reliable published material does not, at this stage, warrant inclusion of SACs … into the noise impact assessment planning stage (EPHC, 2009).
  • While a great deal of discussion about infrasound in connection with wind turbine generators exists in the media there is no verifiable evidence for infrasound and production by modern turbines (HGC Engineering, 2007).
  • There are no direct pathological effects from wind farms and that any potential impact on humans can be minimised by following existing planning guidelines. (NHMRC, 2010)

National Health and Medical Research Council Public Statement

“Infrasound from Wind Turbines: Fact, Fiction or Deception?” Geoff Leventhall

What do you think the scientific evidence shows? What are the ‘placebo’ and ‘nocebo’ effects?

I spy with my little eye…….

Image source

Learning Intention: Students will understand the structure and function of the human eye and investigate how it works and some of it’s limitations.

Success criteria: Students will be able to draw and label a diagram of the eye and describe how it works. They will also be able to give a brief demonstration of an optical and visual phenomena.

This site, by Michael Bach, has not quite 100 different visual illusions for you to examine. The emphasis here is on relative novelty and interactivity, in combination with a scientific background. The National Institute of Environmental Health and Safety have a kids page with some very interesting examples of visual phenomena. There are some more you can try out at Optical Illusions 1,2,3.

Change blindness is a is a psychological phenomenon that occurs when a change in a visual stimulus goes unnoticed by the observer. Here are some examples of change blindness. There are some more examples, using the “mud splash” phenomena here.

The following activities are sourced from the CSIRO “Science by Email” archives. They are all about sight and perception. I would like you to work in pairs to read the instructions, set up the experiment or demonstration and then explain it to the class.

1. Blind spot

2. Lasting color

3. Corner of your eye – peripheral vision

4. Coloured words – the “Stroop” effect

5. Look into your eye

6. How a filter works

7. Phantom eyelids

8. Are you predator or prey?

9. Persisting illusion

10. Pepper’s ghost (this one takes a bit longer to set up)

11. Make a mirage

12. Invisible coin

13. Why is the sky blue? Or pink?

14. Puzzling pendulum

Landing Time of a Parachute – Air Resistance

Creative Commons image from Wikimedia

Learning Intention: To investigate the effects of forces and to design, carry out and report on a simple practical experiment with controlled variables.

Success Criteria: Students will design and carry out an experiment to find out the effect of different factors (mass of object, size of canopy or shape of canopy) on the landing times of a parachute with a toy (Barbie, toy soldier or Lego man) attached. They will vary only one factor, collect data to gain an average of at least three ‘jumps’  and record their results in a table. Students will complete a report of their investigation that includes Aim, Method, Materials, Results, Discussion and Conclusion.

When objects are dropped from a height, gravity is not the only force acting upon them. You would feel the other forces if you jumped from a plane, as air resistance. The picture above shows the design of the world’s first human parachute – can you think of any animals use air resistance to aid movement?

Your task this week is to find out the effect of one of the following variables (something that changes) on the landing time of a parachute. You can use cotton or nylon thread to attach the parachute and drop it from at least two metres.

  • Mass of the skydiver (use a Barbie doll, toy soldier or Lego man with weights added)
  • Size (area) of the canopy (use plastic freezer bags or garbage bags)
  • Shape of the canopy

Make sure that only one of these factors changes and repeat each trial at least three times. Draw up a table to record your results.

 

Year 7 Science: Forces

Magnet and Compass

Click to Run

 

 

Interactive Learning Object from PheT, Colorado

Learning Intention: Students will understand that forces can start motion, stop motion, change the speed or direction of motion, change the shape of an object or have no effect at all. They will be able to distinguish between contact forces (friction, buoyancy, surface tension, mechanical forces) and non-contact forces (magnetic and electric forces).

Success Criteria: Students will create a 60 second science video that demonstrates their understanding of forces.

This term Year 7 students will continue learning about forces, using simple experiments with magnets, water, weights and wires. We will also use some online and netbook tools to learn about forces. Click on the interactive above to enter the learning object. Read more about the magnetic field of the earth at BBC Bitesize: Magnetic Fields.  Do-it-Yourself magnetic levitation at You Tube. Everything you ever want to know about magnets from the Cool Magnet Man. 

Your task this week is to produce a 60-second science video that demonstrates your understanding of forces – choose one of the forces we have discussed (magnetic, friction, static-electric, buoyancy, surface-tension, gravity, muscular and mechanical forces). Create a story board and a script before you borrow the cameras and start filming and editing. You will need to register on the site using a username and password before you upload your video.

Year 9 Science: Electrical Circuits

Image Source

Learning Intention: Students will be able to distinguish between current and voltage and know how they are both measured. They will be able to describe the components of an electrical circuit (switches, loads, resistors, capacitors, cells, insulators and conducting wires) and how they work. Students will be able to construct simple series and parallel circuits and add ammeters and voltmeters to measure current and potential difference. They will understand the relationships between power, energy and time and describe in quantitative terms the relationship between current, resistance and voltage in a variety of electric circuits.

Success Criteria: Students will build a variety of series and parallel circuits and draw their corresponding circuit diagrams. They will perform a variety of practical experiments to measure voltage and current and calculate resistance. They will be able to describe circuits and how they operate using the correct terminology.

This online game, ElectroCity, is a great way to learn about energy, sustainability and environmental management. As the city mayor, you make decisions about the construction of electricity generation plants (coal, gas, solar, nuclear, wind or ocean?)  and where residential and industrial development occurs. If you play the game, add the code BG28135 so I can track your progress.

Dark and Stormy Night

Nick&James_torch

Learning Intention:
Students are learning to identify the important components of an electric circuit and describe how it works.
Success criteria:
You will be able to collect the materials and connect them together to create a torch which includes a globe, switch, wires, batteries and reflector.

This week you will draw what you think is inside a torch (without dismantling it!) and then, after some discussion about the essential components, construct your own torch from simple materials. Imagine you are driving down the back paddock with Dad, and you get bogged in the ute. Dad has to walk back to get the tractor, to pull the ute out. It’s getting dark, so Dad tells you to wait in the car until he gets back. You look in the glovebox and find the following materials:

Batteries
Wires
Sticky tape
Drawing pins
Aluminium foil
Cardboard tube
Paper
Paper clips

You unscrew the globe from the overhead light in the ute and start to make a torch. Your torch needs to be operated with one hand, and have a switch that turns the light on and off. A good torch will be able to direct a beam of light and have no loose wires or dangly bits. When you have finished please leave me a comment about what you found easy, what was more difficult and what you learnt from this activity. What do you think is the most important part of the torch?

Year 7 Transferring and Transforming Energy – Light and Heat

light_painting

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Learning Intention: Students will understand the transfer and transformation of heat and light, including how energy is wasted.

Success Criteria: Students will be able to describe how different types of energy (chemical, electrical etc) can be transformed into heat and light. They will distinguish between conduction, convection, absorption, reflection, transmission and radiation.

  • What does luminous, incandescent and flourescent mean?
  • How do bio-luminescent organisms (glow-worms, some deep sea fish and phosphorescent algae) produce light?
  • What makes a rainbow?
  • What are polarised sunglasses?
  • Why can’t you see through tinted windows?
  • How do some animals see in the dark?
  • Why can’t anyone hear you scream in space?
  • What is a wave?
  • Why can’t humans hear sounds that some animals can? (a dog whistle for example)