Compressibility of Fluids Unit Fluids Compressibility n Does

Compressibility of Fluids Unit: Fluids

Compressibility n Does a water-filled balloon bulge and move in the same way as an air-filled balloon when it is squeezed? n n Air and water tend to flow from one place into another when you try to compress them or squeeze them into a smaller place. Which can be compressed more easily – gas or liquids? Why? n Complete class demonstration: Compressing Fluids

Compressibility n The previous demonstration shows that air (a gas) can be compressed into a smaller volume much more easily than water (a liquid) can. n Why do you think this happens (Hint: think of the particle theory)? n n n The particles of a gas are much farther apart than those of a liquid, allowing us to force the particles of a gas closer together. There is less space between the particles of liquids, so they have very little compressibility, while solids have none at all. Compressibility: The ability of a substance to become more compact when squeezed.

Types of Fluid Systems n Systems designed to squeeze fluids can be divided into 2 main types: n Pneumatic Systems – Use pressurized air or other gases to do work. n Hydraulic Systems – Use pressurized liquids (often oil) to do work n These systems must keep their fluids contained within them in order to work. They are called Closed Systems. n Closed Systems – Systems in which no material enters or leaves the system.

Types of Fluid Systems n Hydraulic and pneumatic fluid systems consist of several components: n n n A pump that forces fluids through a system (e. g. , cylinders and pistons) Conductors that provide a pathway to carry the fluid (e. g. , tubing, hoses, or pipes) Valves to keep the fluid moving in the desired direction at the desired time A pressure gauge that monitors pressure within the system. Pneumatics & Hydraulics Video: n n Part 1 Part 2

Activity: Investigating Fluids in Closed Systems n Remember: n n n Hydraulic systems are less compressible than pneumatic systems, which make them better at transferring great forces quickly (they are more powerful). Pneumatic systems are less dangerous to the environment, can be an open system, and can be smaller than hydraulic systems. Lab: Investigating Fluids in Closed Systems