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Boomerangs
Boomerangs
Boomerangs
Boomerangs
Boomerangs
Boomerangs
Boomerangs
Boomerangs
Boomerangs
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Boomerangs
Boomerangs
Boomerangs
Boomerangs
Boomerangs
Boomerangs
Boomerangs
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Boomerangs

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2009 winning techno challenge powerpoint. by Justin and Josh

2009 winning techno challenge powerpoint. by Justin and Josh

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  • 1. By Joshua Wigley & Justin Thomas Ruskin Park Primary School
  • 2. What are boomerangs
    • Boomerangs are curved pieces of wood used as weapons and for sport. Boomerangs come in many shapes and sizes depending on their geographic or tribal origins and intended function. The most recognizable type is the returning boomerang, which is a throwing stick that travels in a elliptical path and returns to its point of origin when thrown correctly. Although non-returning boomerangs (throwing sticks or kylies) were used as weapons, returning boomerangs have been used primarily for leisure or recreation. Modern returning boomerangs can be almost any size and are made from a variety of materials.
    • Not all boomerangs return, they have to be a certain shape.
  • 3. Boomerangs were first invented by the aboriginals. They were hunting for a kangaroo and threw a stick that they had made it missed the kangaroo and came back. They had accidently created a boomerang . Boomerang in aboriginal means birgan and barragadan
  • 4. How the boomerang works
    • The boomerang works by spinning like a gyroscope.
    • Because you throw it on an angle, like a gyroscope, it stays on the same angle and that’s why it comes back.
  • 5. Gyroscopes
    • The gyroscope is set spinning so that it’s axel is horizontal and the wheel is vertical.
    • The whole gyroscope rotates around the spin axis that runs around the axle.
    • The gyroscope is now placed so one end of the axle is free to move.
    • Gravity tries to pull this end downwards rotating the gyroscope around a second axis, the gravitational axis.
    • At this point precession occurs instead of obeying the pull of gravity, precession makes the gyroscope move in a horizontal circle – in effect rotating it about a third axis.
  • 6. Diagrams of a gyroscope. The precessional movement is the same for when a boomerang spins around and returns to the thrower.
  • 7. But what’s that got to do with a boomerang?
    • A boomerang when it is thrown correctly spins at an angle like when a gyroscope spins. If there is enough speed and thrust from the thrower it will keep the boomerang going and the boomerang will spin on its “spin axis” and return to the sender.
  • 8. This is the spin axis on the boomerang . Here is a diagram of a boomerang showing the point where the spin axis is.
  • 9. These are videos of us using a wheel and a toy to show how a gyroscope works.
  • 10. Boomerang types
    • There are 3 types of boomerangs
    • Beginner boomerang
    • Intermediate skill boomerang
    • Advanced and competition boomerang
  • 11. Beginner boomerang
    • Boomerangs for beginning throwers are usually the traditional V-shaped ones or three bladed boomerangs called tri-bladers.
    • Tri-bladers and other beginner boomerangs are generally very light and don't require a very strong throw.
    • Because of their lightness they should not be thrown in windy conditions.
    • These are good boomerangs to learn on and improve your throwing technique before moving up to heavier, intermediate skill boomerangs.
    • Range (how far the boomerang travels away from the thrower before returning) is about 10-25 meters.
  • 12. Intermediate skill boomerang
    • Intermediate boomerangs can be any size and are typically heavier than beginner boomerangs.
    • They will require a harder throw but will work better in windier conditions.
    • Some will need a little more technique in the throw but are capable of differing flight paths, depending on how they are thrown.
    • Range can be from 30-50 meters.
  • 13. Advanced and competition boomerang
    • Advanced boomerangs can be any size depending on what the thrower wants the boomerang to do.
    • They can range in weight from ultra-light MTA (Maximum Time Aloft) boomerangs designed to stay in the air for a long time to heavy, lead weighted boomerangs designed to travel a long distance before turning to return to the thrower.
    • Flight paths are extremely varied, depending on the boomerang and all require a certain amount of practice and skill to throw successfully.
  • 14. Throwing instructions
    • Safety rules
    • never throw a boomerang at or to anyone.
    • Allow plenty of room for throwing. A large oval or park is ideal
    • Never throw your boomerang in gusty or windy conditions, particularly while at the learner stage. A day that is mild with a light wind is ideal.
    • Never catch your boomerang at eye level. Always wait until it is below shoulder height
    • Never throw your boomerang laid over flat like a Frisbee. Always have the boomerang nearly vertical on release to avoid dangerous diving and swooping flights.
    • Don't throw too hard at first. Half powered throws are enough to return most models. As you gain experience you can add more power for longer range and duration of flights.
  • 15. Safety first when playing with Boomerangs. Safety first when playing with Boomerangs .
  • 16. How to hold it
    • The curved or decorated side should be held towards you and the flat side away.
    • The easiest way to grip the boomerang is to make a closed fist and insert the boomerang between the thumb and first finger.
    • Make sure the boomerang is cocked back along your arm for maximum spin. The "elbow" can be pointing either forward or back as shown. see which grip suits you best.
  • 17. How to throw it
    • Throw with a normal over arm style facing 45 degrees to the right of the wind (to the left if you are left handed).
    • Aim the boomerang at a point on or just above the horizon.
    • It is important to make sure that you give it a good flick on release so that it will spin well.
  • 18. ALLOWING FOR THE WIND
    • To find out where the wind is coming from pick up some grass and drop it, hold up a hanky or lick your finger and hold it up in the air etc.
    • Throw to the right of the wind about 45 degrees (to the left if you are left handed) so that the breeze helps the boomerang come back.
  • 19. LAUNCH ANGLE
    • The boomerang should be nearly vertical on release.
    • Increasing the tilt angle makes it fly higher and land further back.
    • Holding it more vertically makes it fly lower and land further forward.
  • 20.
    • Catch it between you hands in a clapping motion as shown here as it hovers down near you.
    • Aim for the central section of the boomerang and avoid catching the fast moving wing tips.
    Catching your boomerang
  • 21. Wings giving lift
            • The boomerang’s wing is the shape of a planes wing, both are curved on top and flat underneath.
            • Because there is more surface area on the curved side for the air to go over, the air is thinner and lighter than the air that travels along the flat underneath side which is more dense.
            • The denser air pushes the boomerang’s wings up like an aeroplane’s wings
  • 22. Secret talent We found out that our Japanese teacher taught how to throw a boomerang when he went to Japan. He made a boomerang and he let us use it.
  • 23. THIS WAS THE FUN PART – TRYING TO THROW THE BOOMERANG Mr Brown showed us how to check the wind direction and how to position the boomerang and which direction to throw it in. We tried and tried and tried but couldn’t get it to come back without any wind. Even Mr Brown had trouble.
  • 24. Here is a video of a man throwing a boomerang and it actually came back. He throws the boomerang very powerfully
  • 25. At school our teacher Mr Brown showed us how to throw a boomerang. This is us trying our hardest. But without any wind it was difficult.
  • 26. We found that one of our teachers at Ruskin Park is actually a boomerang expert. He showed us how to throw the boomerang correctly. It’s good to actually try out what we learned.
  • 27.
    • Today, boomerangs are mostly used as sporting items.
    • There are different types of throwing contests: accuracy of return; Aussie round; trick catch; maximum time aloft; fast catch; and endurance .
    Modern use
  • 28. We made our own boomerangs Josh made these boomerangs from cardboard. We tried them out and compared them to the traditional style. Josh made six different Boomerangs so we could test and see which one was the best. BEST WORST
  • 29. We tested them too It worked – how good was that!
  • 30. The boomerang in action This animation is from the internet
  • 31.
    • Kylie is one of the Aboriginal words for the hunting stick used in warfare and for hunting animals.
    • Instead of following a curved flight path, it flies in a straight line from the thrower.
    • They are typically much larger than boomerangs.
    • It can travel very long distances, and due to its size and hook shape can kill an animal or human opponent.
  • 32. There are lots of songs about boomerangs . The most famous Aussie song is called “ My Boomerang won’t come back”. Slim Dusty wrote one called “Boomerang” ABBA also had a song called Bang a Boomerang and John Williamson had one called Boomerang Café.
  • 33.
    • I hope you liked
    • our
    • powerpoint.
    • We had fun
    • making it
    • and learnt
    • a lot.
  • 34. Info
    • We would like to give a thanks to the following references that we used
    • Wikipedia
    • boomerang.org
    • www.boomerangs.com
    • Howstuffworks.com
    • Wiki how
    • www.rangs.co.uk/flightmovie.htm
    • ‘ Ready for take-off’ –Robin Lawrie
    • ‘ The way things work’-David Macaulay
    • Mr Greg Brown
    • Mrs Margot Pope
    • Movie converter to convert the avi movies so they played in powerpoint.
    • Pivot animation program from the internet
    • GraffitiGen.com
  • 35. Quiz time
    • What is a Kylie?
    • A person
    • A hunting stick
    • A good name for a dog
    • None of the above
  • 36. Wrong Answer Try again
  • 37. Right Answer Continue
  • 38. What are the best conditions for throwing a boomerang?
    • A very windy day
    • A mild day with light wind .
    • A hot dry day with no wind .
    • A rainy day .
  • 39. Wrong Answer Try Again .
  • 40. Right Answer Continue
  • 41. How did you go? Good Bad
  • 42. Well done, now you can enjoy our bloopers. Continue
  • 43. Never Mind. You can watch the presentation again or just enjoy the bloopers that follow. Continue
  • 44. Bloopers All good movies have bloopers don’t they?
  • 45. Testing is great fun! I can catch it!
  • 46. The real ending….. Thanks for watching.
  • 47. What’s next ? Learning about the boomerang has made us wonder how so many other things might work. Airplanes Helicopters Hover Craft Hot Air Balloons Gliders Space Ships Kites Watch this space …….

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