140 likes | 258 Views
Water properties. Why do we want to explore the ocean?. The Oceans are the number one driver of weather and climate They are also important for transportation and food To learn about the organisms that live there
E N D
Water properties www.pwssc.org
Why do we want to explore the ocean? • The Oceans are the number one driver of weather and climate • They are also important for transportation and food • To learn about the organisms that live there • Almost every type of plant and animal known to science can be found in the ocean www.pwssc.org
What is it like underwater? • Dark • Deep • Lots of pressure • Big • Cold • Salty www.pwssc.org
Three Properties of Water Density Pressure Buoyancy www.pwssc.org
Density • How much “stuff” is in a certain amount of “space” • Mass is the amount of matter (stuff) in an object. • Volume is the amount of space an object takes up. www.pwssc.org
Density Example • A rock and a crumpled piece of paper are the same size. They have the same Volume. • The rock weighs more than the piece of paper, it has greater Mass. • Which item has a greater Density? www.pwssc.org
Density and States of Matter Solid Liquid Gas Density refers to how closely "packed" or "crowded" the material appears to be http://www.cofc.edu/~martine/111LectWeek1_files/image008.jpg www.pwssc.org
Pressure • How much force is applied to an area. • Measured in Pascals (Pa), atmospheres (ATM), or pounds per square inch (psi) • There are many other units as well! • Water pressure is caused by the weight of water pressing down on what is beneath it. • The deeper you go, the more water is above you, the greater the pressure. www.pwssc.org
Water Pressure • Water and air are both fluids. • Water is more dense than air, so it “sinks.” • In a bottle with half air and half water the water stays at the bottom. www.pwssc.org
Units of Pressure • At sea level the pressure is equal to: • 101,325 Pa • 14.7 psi • 1 ATM • Our bodies are used to this level of pressure, they exert the same amount of pressure back. • Underwater • 10 meters (33 feet) of water above you will exert 1 ATM of pressure www.pwssc.org
Water Pressure • This Styrofoam cup was sent to 1279 m and felt 1833 psi or 125 atmospheres of pressure • Why caused the cup to get smaller? • Has the density of the cup changed? http://iodp.tamu.edu/scienceops/gallery/exp311/week7/pages/exp311_107.html www.pwssc.org
High Pressure Adaptations Animals that live in the deep have adapted to a high pressure environment. • No excess cavities • Soft, pliable bones www.pwssc.org http://ocean.nationalgeographic.com/ocean/photos/deep-sea-creatures/
Buoyancy • The ability of something to float in a fluid (water, air, etc.) • Archimedes Principle: An object is buoyed up by a force equal to the weight of the fluid displaced by the object. www.pwssc.org http://en.wikipedia.org/wiki/Image:Buoyancy.svg
States of Buoyancy • Positive Buoyancy (float) The weight of the object is less than the weight of the displaced water. • Negative Buoyancy (sink) The weight of the object is MORE than the weight of the displaced water. • Neutral Buoyancy (hover) The weight of the object is the SAME as the weight of the water displaced. www.pwssc.org