Propeller pow er A propeller has blades th at push air along as the propeller spins. The blades are angled
to push the air like a wedge. The blades are twisted because they m ove much faster at their tip s th a t at
their roots.
Air-pow ered craft Most water craft are driven by propellers under the water. Air propellers are used for
craft th a t work in very shallow water, where a propeller would hit the bottom , or get caught in w ater plants.
The two most common air-powered craft are hovercraft and airboats, such as the Bottle C a ta m a ra n .
W hy th e B ottle Catam aran flo ats Boats float in water because the water pushes up on them . Scientists
call this push upthrust. The size of the upthrust depends on how much w ater the boat pushes o u t ofthe
way as it sits in th e water. As the Bottle Catam aran floats dip further into the water, they push m oreand
more water aside, and so the upthrust get larger. When the upthrust becomes equal to the w eight ofthe
boat pushing down, the boat floats.
GREEN SCIENCE
Build a better tomorrow through education & awareness. You will like the other great Green Science k i n
00-03266 Soda C an Robug
Millions of soda can are wasted everyday. Help save our
environm ent. Recycle one of them and turn it into a cool
robotic bug. Switch it on and watch it vibrate causing it
to slide across the floor. It even emits a “ b u zz” as it
moves along - just like a real bug. It's an awesome
robtic science kit.
00 -0 3 267 Windmill Generator
Build this am azing wind generator learn about
renewable energy. Watch the L E D glow as it is p o w e rd
by free energy from the w ind. No batteries required !
Questions & Com ments
. ;
We value you as a custom er and your satisfaction with this product is im portant to us. If you have comm ents or q ue stic is ,
or you find any part of this kit m issing o r defective, please do not Hesitate to contact our distributor in your c o u n try, tn i
will fin d the address printed on th e pa ckage. You i r e also welcome to contact our Marketing Support T e a m : Em ail:
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