Properties of Fluids

1. Forces in Fluids Chapter 23

2. Thought Questions Why is the electricity produced at the bottom of dams? When you catch a deep-sea fish, why does its eyes pop-out? Why do your ears pop on an airplane or up in the mountains?

3. Pressure Pressure is equal to the force applied to a surface, divided by the area.

6. Low Pressure L Rising Air Suction L

9. Astronomical telescopes are placed on mountain tops because the thinner air means less interference with the starsMauna Kea at 13,700 feet Is above 40% of the atmosphere

10. Extreme Elevations Commercial flights fly higher than you can breathe. So, they must pressurize the cabin Mount Everest at 29,600 feet Is above 70% of the atmosphere 35,000 feet

11. Extreme Elevations Astronauts have no actually left the atmosphere. The microscopically thin atmosphere results in drag on spacecraft and satellites. Nonetheless, it is far too thin to breathe and cold to survive without spacesuits 100 km

12. Highest Pressure Very Low pressure Higher Pressure The whole system is a low pressure, but it is extremely low in the eye.

13. Highest Pressure Very Low pressure Higher Pressure Pressure always flows from high to low, which creates the high velocity winds toward the eye.

14. Storm Surge Very Low pressure Higher Pressure The Low Pressure creates a vacuum that pulls water up into a dome. The high winds push this dome on shore.

15. Storm surges are the leading cause of damage Very Low pressure Higher Pressure The force of the air moving toward the eye causes extreme winds in excess of 100 mph.

20. Hydraulic Devices In a hydraulic device, a force applied to one piston increases the fluid pressure equally throughout the fluid.

21. Hydraulic Devices By changing the size of the pistons, the force can be multiplied.

22. Hydraulic Brakes The hydraulic brake system of a car multiplies the force exerted on the brake pedal.

23. Buoyancy The tendency or ability of an object to float.

24. Buoyancy The pressure on the bottom of a submerged object is greater than the pressure on the top. The result is a net force in the upward direction.

25. Buoyant Force The upward force exerted by a fluid on a submerged or floating object.

26. Buoyancy The buoyant force works opposite the weight of an object.

27. Archimedes’ principle: Buoyant Force on an object immersed in a liquid equals the weight of the liquid displaced.

28. Density and buoyancy: An object that has a greater density than the fluid it is in, will sink. If its density is less than the fluid it will float. Density

29. It does not matter that Mercury is a liquid. It is so dense, most things float on it

30. Buoyancy of gases in liquids Buoyancy of gases in gases Gases have less density than water, so they rise up to the surface Some gases, like Helium, are lighter than air and rise. Some gases, like carbon dioxide, are heavier than air and sink.

31. How do super heavy container ships float?

32. A solid block of steel sinks in water. A steel ship with the same mass floats on the surface.

33. A solid block of steel sinks in water. A steel ship with the same mass floats on the surface. Air steel

34. Take the mass of the displaced area (steel and air) and compare it to the mass of the water of that volume. If the displaced area weighs less it will float. Water

35. Density Changes in density cause a submarine to dive, rise, or float.

36. Density Changes in density cause a submarine to dive, rise, or float.

37. Density Changes in density cause a submarine to dive, rise, or float.

38. Density Gases can actually be made from solids using chemical reactions to create additional buoyancy.

39. DENSITY OF WATER 1g/cm³ or 1 g/ml