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 | You'll need these things. | |  | Put the orange in the water. | |  | Peel the orange and put the orange flesh into the water. Add a piece of peel. | | Try this: Orange life jacket You will need - An orange
- Water
- Large bucket or bowl
What to do - Fill the bucket or bowl with water.
- Drop in the orange. Does it float?
- Take out the orange and remove all of the peel.
- Drop the orange flesh into the water. Does it still float?
- Try dropping a piece of peel into the water. What happens?
What's happening? Look carefully when you put the orange into the water and you might see the water level rise. When any object goes into water, it pushes some of the water out of the way. It's called displacement, and you'll also see it happening when you get into a bath. Your body displaces water, and the water level rises. An object sinks when it weighs more than the water it displaces. The object goes down because it is heavier than the amount of water that has to go up. When you first put the orange into water, it floats because it is lighter than the amount of water that it displaces. But take off the peel, and you'll find the flesh of the orange is heavy, and the peel is light. Orange flesh contains water, sugar and other bits and pieces that makes it heavier than if it was just all water. Orange peel has pockets of air which makes it lighter than the water it displaces, so it floats. Applications The orange peel acts like a life jacket; it keeps the orange flesh floating when its on, but without it the orange will sink. When people go sailing, they wear life jackets so they will float better in water. Ships use water displacement to keep afloat. Even large tankers can float because of their shape and pockets of air within the metal hull.  | CREST question: Does the same thing happen with other fruit? Design an experiment to test this.
| More information By Sarah Kellett View the online version |
Quiz questions 1. What is considered the fear centre of the brain? 2. When talking about dark matter, what is the acronym for massive compact halo objects? 3. Fill in the blank: In 1990, Toyohiro Akiyama became the first ___ in space? 4. At what temperature do water droplets in clouds spontaneously form ice crystals? a) 0 degrees Celsius, b) –20 degrees Celsius, c) –40 degrees Celsius. 5. Prospecting is the search for minerals. What is bioprospecting? |
The Gutsy Challenge Now in its second year, the Gutsy Challenge is a national healthy eating program for school children. Students take the challenge to eat two fruit and four vegetables each day for one week, raising money for digestive cancer research and clinical trials. The Challenge can be undertaken any week during Term 3, between 18 July and 30 September 2011. Participants can register online and record food eaten and play nutrition games. Teachers can utilise online learning resources from the site. |
Did you know? Large doses of radiation are dangerous, but small amounts might make people healthier. Flinders University research is finding out whether low dose radiation can reduce or prevent prostate cancer. |
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Events Vic: Brave New World Should we be researching useful microbes to store carbon and slow climate change? Plants feed us and nature sustains us but could microorganisms give us the 'biggest bang for our buck'? Can we solve tomorrow's environmental and energy problems using life itself? When: Wednesday 27 July 2011, 12.30 pm to 1.30 pm Where: Melbourne Convention and Exhibition Centre How much: Free For more information, see the International Botanical Congress website or email Janelle Hatherly at Janelle.Hatherly@rbgsyd.nsw.gov.au. |
Urban Ecosystems, Saturday 23 July at 9.00 am on Network Ten Crows, magpies, ant-lions, ibises; there are many animals that live amongst us in our urban environment – so how do they do it? This week on SCOPE we are looking at the animals with which we share our lives. We go looking for turtles, find out how to re-create the outback in the middle of a city and go hunting for ant-lions. So join Dr Rob as he once again proves that the ordinary really does become extraordinary, under the SCOPE!
Next episodes: Thursday 28 July: Solar system Saturday 30 July: Rockets Want to have your own episodes of SCOPE to watch whenever you feel like it? Click here to download them directly into your iTunes folder, or go here to download iTunes. Charges apply. |
| CSIRO Education incursions and excursions Each year, over 260 000 students, teachers and other visitors come to CSIRO Education's regional centres or are visited at schools by our staff. Click here for more details on your nearest centre. Teacher's Guides Bring new ideas to your classroom with the Science by Email Teacher's Lounge, Scientriffic Teacher's Guides and The Helix Teacher's Guides, including lesson plans, black-line masters and other support material for teachers. BHP Billiton Science Awards The BHP Billiton Science Awards reward students for creative research, experiment or investigation projects and teachers for their support of open-ended student investigations. For more details, click here. | |
Quiz answers 1. The amygdala is considered the fear centre of the brain. It is involved in organising responses to danger and learning new threats. 2. MACHOs is the acronym for massive compact halo objects, found in dark matter. 3. In 1990, Japanese journalist Toyohiro Akiyama became the first fare-paying passenger to go into space. The round-trip cost about $12 million. 4. c) Water droplets in clouds spontaneously form ice crystals at –40 degrees Celsius. 5. Bioprospecting is the search for new chemicals in living things that could be useful in medicine or industry. CSIRO are using bioprospecting to find health benefits in food. |
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