1. 1 Non-Terrestrial Transportation Boats Rafts, Sailboats, Ships, & Hydrofoils Aircraft Planes, Passenger Jets, Helicopters

2. 2 Blowing on paper Buoyancy Kit (tin foil, washers) Cartesian Diver Blower and Ping Pong Sailboat and Track SpoonFairy 2

3. Early Boats Hollowed out logs Hollowed out logs Reed rafts Reed rafts www.tulsaweb.com Pirogue Redwood Grove, Los Altos Pronounced: \pē-rōg\

4. 4 Overcoming Gravity Gravity acts the same on all objects - exerts greater forces on larger masses and smaller forces on less massive objects such that the downward acceleration is the same for all objects 4

5. 5 Objects suspended in fluids (air and water) Buoyancy Force counteracts the weight of the object: 5 mg = F buoyancy

6. 6 Fluids exert pressure Atmosphere at sea level exerts 14.7 psi (lbs/in 2 ) in all directions due to gravity pulling down on the column of air above our heads. Pressure decreases at higher elevations. 6

7. 7 Water not moving 7

8. 88 Forces due to pressure = Net Buoyant Force Net Buoyant Force = Weight of water Water not moving

9. 99 Forces due to pressure have not changed Net Buoyant Force = Weight of water displaced Replace water with object

10. 10 If weight of object < Fb (object rises) If weight of object > Fb (object sinks)

11. Archimedes and Buoyancy i.e. some things fall “up”! Before discovering the Lever and the Screw for lifting water, Archimedes discovered buoyancy. Before discovering the Lever and the Screw for lifting water, Archimedes discovered buoyancy. Archimedes Principle states that the buoyant force on a submerged object is equal to the weight of the fluid that is displaced by the object.

12. This Concept is best seen with Hot Air or Helium Balloons The balloon rises because the weight of the balloon, gondola, and the internal gas is less than the air displaced by the balloon. This is called upthrust.

13. What would you weigh if fully submerged in water? (Your weight – the wt. of the water displaced) (Your weight – the wt. of the water displaced) 100 lbs. What figure weighs more in the pool?

14. Cartesian Diver By squeezing the bottle the pressure increases. The air in the condiment package compresses, lowering its volume. By squeezing the bottle the pressure increases. The air in the condiment package compresses, lowering its volume. Less water is displaced if the condiment package is compressed, making the package less buoyant. Less water is displaced if the condiment package is compressed, making the package less buoyant. http://www.sciencetoymaker.org/diver

15. Water going vessels can be very heavy as long as they displace enough water The vessel will float if it displaces water equal to the weight of the boat (including cargo). It must do this without taking water over the sides The vessel will float if it displaces water equal to the weight of the boat (including cargo). It must do this without taking water over the sides The Ice Breaker – has an armored steel hull www.tq-international.co

16. Materials that are denser than water such as steel can be made to float on water as long as the steel object can displace an amount of water equal to its weight. Many Civil Engineering programs build and compete in a Concrete Canoe event. http://uwnews.org

17. Three similar sized pieces of tin foil One floats One floats One sinks One sinks One appears suspended One appears suspended What’s the difference between them?

18. The Accepted Anthropological Map Showing Migration of Homo Sapiens

19. Drawbacks with Exploration Over Land Restricted by Land (a small percentage of our planet – 29%) Restricted by Land (a small percentage of our planet – 29%) Terrain constraints (mountains, deserts, rivers) Terrain constraints (mountains, deserts, rivers) Enemies Enemies Reliance on stock animals Reliance on stock animals High maintenance wagons High maintenance wagons

20. Benefits and Challenges with Exploration over Water Greater mobility Greater mobility Riskier Riskier Powered by Wind Powered by Wind Density of salt water allows large vessels to float Density of salt water allows large vessels to float Navigation is difficult Navigation is difficult Usually capital Intensive Usually capital Intensive

21. Propelling Boats and Aircraft Oars – for every force there is an equal and opposite force. Oars – for every force there is an equal and opposite force. Action-Reaction Action-Reaction Sails Sails Propellers Propellers Airfoils Airfoils

22. 22 Propellers are Fans 22

23. Helicopters http://science.howstuffworks.com/helicopter.htm

24. Wings Airplane wings exert a downward force on the air. The air pushes up on the wing with an equal force. Airplane wings exert a downward force on the air. The air pushes up on the wing with an equal force. http://www.seed.slb.com/en/scictr/watch/sailing/index.htm Umbrella Animation

25. Airfoil A surface designed to produce lift from the movement of air over it. A surface designed to produce lift from the movement of air over it. http://www.aircommand.com It is the Coanda Effect that gives the fluid the tendency to follow the contour of the upper surface rather than traveling in a straight line. Wikipedia

26. The Coanda Effect http://www.allstar.fiu.edu/AERO/airflylvl3.htm Newton’s 3 rd law indicates that the fluid forces the object to the right as it travels along the surface to the left. Fluid flow

27. Getting Lift with Airplanes http://howthingswork.virginia.edu/airplanes.html A really good explanation. http://www.allstar.fiu.edu/AERO/airflylvl3.htm A much more detailed explanation. much more detailed explanation. Lift comes from the air around the wing that is diverted downward. LIFT: Vertical force DRAG: Horizontal force

28. 28 Would this Airfoil Produce Lift? 28 Yes, but drag force is excessive.

29. The four forces Lift Lift Drag Drag Weight Weight Thrust Thrust http://www.eng.fsu.edu/~ugartjo/Drag.htm

30. Sailing on a Tack (against the wind) http://sail-boats.suite101.com

31. Sailboat Demonstration Blow air at a 45 0 angle of attack to show that the pulling force is greater than the pushing force, producing a net force in the windward direction Blow air at a 45 0 angle of attack to show that the pulling force is greater than the pushing force, producing a net force in the windward direction http://www.seed.slb.com/en/scictr/watch/sailing/index.htm Good Animation of Sails and angle of attack

32. As air moves faster its pressure decreases. Throwing a curve ball as demonstrated by a good pitcher Throwing a curve ball as demonstrated by a good pitcher Shower Curtain problem Shower Curtain problem Blowing air across paper to make is rise Blowing air across paper to make is rise Blow Dryer and ping pong trick Blow Dryer and ping pong trick http://wings.avkids.com/Book/Sports/instructor/curveball-01.html

33. Propellers have the shape of airfoils http://www.athropolis.com/

34. Forces from Ailerons and Elevators A lowered Aileron produces Lift, while a raised Aileron reduces Lift. The two Ailerons make the aircraft roll. A lowered Aileron produces Lift, while a raised Aileron reduces Lift. The two Ailerons make the aircraft roll. Elevators are at the rear and control the pitch. Elevators are at the rear and control the pitch. http://en.wikipedia.org/wiki/Aileron A good animation here. http://en.wikipedia.org/wiki/Elevator_(aircraft)

35. Plane Components http://www.centennialofflight.gov/about/index.htm

36. Hydrofoil Hydrofoils are used to ferry people across the English Channel. Hydrofoils are used to ferry people across the English Channel. The hydrofoils produce lift, raising the boat out of the water. Once above the surface, the boat can skim over the top as it is relatively unaffected by waves. Surface Piercing Foil follows the contours of the waves. www.maths.otago.ac.nz

37. http://www.hydrofoil.com/hitest/reference.html The hydrofoil in inherently stable because when it leans to one side more of the foil on the low side is submerged, increasing the lift on that side. Thus the boat ‘rights’ itself. Also this hydrofoil follows the contours of the waves. When it travels into a wave, more the foil goes underwater giving the boat greater lift. When it travels out of a wave, less of the foil is underwater, therefore the lift decreases.

38. 38 How do spacecraft maneuver in the absence of air? Newton’s 3rd Law Newton’s 3rd Law High Pressure Fuel Exerts a force on one side of rocket while being released out the back. High Pressure Fuel Exerts a force on one side of rocket while being released out the back. 38