1. Fluids and Motion

2. Check this out!
Hold up 2 pieces of paper so that the edges are facing you and are about 4 cm apart
Blow as hard as you can between the 2 sheets of paper

3. Daniel Bernoulli
Swiss mathematician in 18th century

4. Bernoulli’s Principle
fluid pressure decreases as the speed of the fluid increases

5. Ping pong ball in water?
What happened to the ball in the running water?
Why did this happen?

6. Blow on a piece of paper
What happens? Why?

7. Attack of the Shower Curtain!

8. Bernoulli’s Principle
The faster the fluid is moving, the lower the pressure it creates.
It will move toward the low pressure!!!

9. Factors that affect flight:
Lift
Thrust
Drag

10. Factors that affect flight:
Fast air = low pressure
Slow air = high pressure

11. 1. Air has to travel faster on top of the wing and creates lower pressure. Slower moving air below the wing has higher pressure. This creates an upward force.

12. Lift - upward force on an object that moves in a fluid

13. 3. Thrust – the forward force produced by the engine

14. Wing size
Jet engines produce a lot of thrust so the wing size can be smaller.

15. Wing Size
Gliders produce no thrust so the wing size must be larger

16. Birds and Flight

17. Birds
Small birds must flap his wings faster to stay in the air.

18. Birds
Large birds can flap slower and still stay in the air

19. How a Curve Ball Works

20. Drag
force that opposes or restricts motion in a fluid

21. Opposes thrust
Resists the movement of objects
Caused by air not flowing smoothly across the surface
Goes with the direction of the airflow

22. Reduce Drag

23. Drag
Often caused by turbulence which is an irregular flow of fluids

24. Turbulence

25. Turbulence

26. Tailgate Up or Down?

27. Drag
Lift is often reduced when turbulence causes drag

28. Factors that affect flight:
Lift
Thrust
Drag

29. Blaise Pascal 17th century French Scientist
Transmitting Pressure Through Fluids

30. Pascal’s Principle
change in pressure in an enclosed fluid is transmitted equally to all parts of the fluid

31. Examples:

32. Hydraulic Devices use Pascal’s Principle

33. Hydraulics
Hydraulic devices use liquids because they cannot be squeezed into smaller areas easily

34. Hydraulics
Hydraulic devices help move heavy objects by multiplying forces

35. Example:
Small push on break can stop a large car