SCI 8: Fluids NAME: _______ANSWERS________ HOMEROOM: _____ Fluids Unit Review 1. Make a list of five fluids that can be found in each of these places. a. The human body – blood, saliva, urine, stomach acid b. A kitchen – maple syrup, dish soap, vegetable oil, oven cleaner c. A Garage – motor oil, windshield washing fluid, gasoline, window cleaner 2. Make a list of ten machines or devices that use fluid power systems. a. Car lift – Hydraulic b. Jackhammer – Pneumatic c. Jaws of life tool – Hydraulic d. Back hoe - Hydraulic 3. Identify five industries where the properties of fluids play an important role. For each industry, provide an example of fluid use. a. Food Industry: Manufacturing of products such as chocolates, syrups, and candies (viscosity) b. Aviation Industry (flight): Hydraulic cylinders on airplane landing gear; Knowledge of properties of air (fluid) are necessary for flight c. Automotive Industry (cars): Hydraulic systems in brakes and steering; Alternative fuel sources such as propane and hydrogen (fluids) d. Construction: Hydraulic systems in equipment such as cranes and back hoes e. Shipping: Knowledge of properties of fluids are necessary for safe loading and cargo; Ballast water systems (buoyancy and density) 4. Identify each of the following as either mass or weight. a. This measures the amount of matter in an object. MASS b. This measures the force of gravity acting on an object. WEIGHT c. This measurement varies according to the location of the object in the universe. WEIGHT d. Unless something is added to or taken away from the object, this measurement of an object remains the same everywhere in the universe. MASS e. This pulling force is measured in newtons. WEIGHT f. This measurement is not a force. MASS 5. Compare how a submarine, a fish, and a scuba diver control their depth in the water. Explain each in detail – what does each one do in order to become less buoyant? And what about more buoyant? a. Submarines: Ballast tanks fill with water to become more dense and to sink down; ballast tanks release/empty water in order to become less dense and rise up again. b. Fish: Swim bladders take in air to become less dense and rise up; Swim bladders release air and become more dense and sink down. c. Scuba Divers: Weight belt helps balance out buoyancy; BCD (Buoyancy Compensation Device) is like a vest or life jacket – divers pump air into the vests to become more buoyant (less dense) to rise up, and release the air to become less buoyant (more dense) to dive down. Kluge 2012 NAME: _______ANSWERS________ HOMEROOM: _____ SCI 8: Fluids 6. Using the Particle Theory of Matter, explain the effects of temperature changes on solids, liquids, and gases. Draw a diagram to support your explanation. SOLID Particle Distribution Strength of particle bonds Particle motion Particles in solids are very close together The bonds between particles in solids are very strong Particles in solids have very little motion; they only vibrate. Density Solids usually have a greater density than liquids and gases Mass Solids usually have a greater mass than liquids and gases. Volume Changes in Density due to Temperature Solids keep their own shape when put into a container; they take up the smallest amount of volume. When you add heat to a solid, its density decreases When you remove heat, its density… increases LIQUID Particles in liquids are farther apart than in a solid, but closer than in a gas. The bonds between particles in liquids are stronger than gases, but weaker than solids Particles in liquids move around very little The density of liquids is usually in between that of solids and gases The mass of liquids is usually in between that of solids and gases. Liquids take on the shape of a container, but they do not fill out the whole container GAS Particles in a gas are quite spread out. The bonds between particles in gases are quite weak Gas particles have a lot of motion; they move around fast and bounce into one another Gases usually have a lower density than solids and liquids. Gases usually have a lower mass than solids and liquids. When you add heat to a solid, its density decreases Gases take on the shape of a container and they take up/fill out the entire space of the container that they are placed in. When you add heat to a solid, its density… decreases When you remove heat, its density… increases When you remove heat, its density… increases 7. Fill in the blanks to complete the sentences. a. The ___flow rate______ of a fluid is an indicator of its viscosity. b. Because the volume of a liquid under pressure changes very little, the liquid is said to be virtually ____incompressible_____. c. Helium balloons float in air because their ___density___ is less than that of air. d. Mechanical systems that use fluids to transmit force and move objects are called __hydraulic_____ or ___pneumatic_____ machines, depending on the fluid used. e. __Hydraulic___ machines use liquids and ___pneumatic_____ machines use gas. f. The buoyant force is opposite the __gravitational____ force on an object in water. 8. A warning on an aerosol can states “Caution, container may explode if heated.” Explain why this might be using the Particle Theory of Matter. Kluge 2012 NAME: _______ANSWERS________ HOMEROOM: _____ SCI 8: Fluids If the aerosol container is placed near a heat source, then the substance inside increases in temperature, which causes the bond strength between particles to weaken, and the particles to move faster. The more heated it becomes, the faster the particles move, and the faster the particles move, the more collisions between them and the walls of the container there are. The more collisions there are between particles, the more pressure builds up inside the aerosol container, and if the pressure builds up enough, then it can explode. 9. Fill out the table below to describe the relationship between the following fluid properties. Bond Strength Volume Density Viscosity Pressure As Temperature Increases Decreases (become weaker) Increases (takes up more space) Decreases (becomes less dense) Decreases (becomes less viscous) Increases (more collisions) As Temperature Decreases Increases (become stronger) Decreases (takes up less space) Increases (becomes more dense) Increases (becomes more viscous) Decreases (less collisions) 10. What are two ways in which the pressure of a confined fluid can be increased? a. Increase temperature – As temperature is increased, bond strength decreases, and particles move around faster; the faster the particles move, the more collisions there are between particles and between the particles and the walls of the container; the more collisions there are, the greater the pressure inside the container. b. Compress the fluid - The more you compress a fluid, the less volume/space there is available for it, and the less space there is available for the particles moving around, the more often these particles collide with each other and with the walls of the container; the more collisions there are, the greater the pressure inside the container. 11. What are the four parts of the Particle Theory of Matter? a. All matter is made up of tiny particles too small to be seen b. These particles attract each other c. These particles are constantly in motion (moving around) because they have energy d. The more energy the particles have, the faster they move (i.e., when you add heat energy, the particles move faster) Kluge 2012