why do ships float

[...]... 7, 10 Cargo ships 12, 13, 22, 23 Compartment (ship) 15 Cruise ships 13 Density 8, 9, 10 Designing ships 12, 13, 28 Destroyers (ships) 25 Displacement of water 4, 5, 14 Diving planes 26, 27 Engines 18 Fish, protection of 17 Floating 4, 6–7, 10–11, 14 Future ships 28, 29 GPS (Global Positioning System) 21 Gravity 4, 6, 7, 10 Helm (steering wheel) 20 Hull 14, 15, 16, 26, 27 Keel 14 Kinds of ships 12, 13... useful devices Modern ships use electronic navigation equipment Many ships also use GPS, which stands for Global Positioning System, to locate their exact position This system involves satellites orbiting Earth A ship can figure out its location by receiving radio signals from several satellites at once 21 Ships_ FNL.indd 21 8/11/09 4:34:38 PM Ships Doing Business E very day, thousands of ships carry people... it was common for companies to overload ships with cargo This caused many accidents at sea To protect sailors, Plimsoll helped pass a law in Parliament It was known as the Merchant Shipping Act From then on, British ships had to have load lines on their hulls 23 Ships_ FNL.indd 23 8/11/09 4:34:40 PM Military Ships T he ships in the U.S Navy have many jobs to do An aircraft carrier, for instance, is... In other words, what is its job? Some ships transport dry cargo like grain and 12 Ships_ FNL.indd 12 8/11/09 4:34:10 PM ore Some cargo ships, called tankers, carry oil Other ships are built for passengers only Still others are used by the military for its missions There are special ships, too, like icebreakers and research vessels Because they have different jobs, ships are laid out in various ways A... Submarine’s Special Rudder Like other ships, a submarine uses its rudder for steering But the submarine’s rudder is shaped differently from the rudders on other ships One part of the rudder stands above the outer hull The other is below it 27 Ships_ FNL.indd 27 8/11/09 4:34:55 PM Ships of the Future I f you could look ahead in time, you would probably see a new world of ships Future vessels will likely be... do work But much of the crew’s job will be watching over the computer and the ship’s other machines Different but the Same The ships of the future will likely be different from today’s ships in many 28 Ships_ FNL.indd 28 8/11/09 4:34:56 PM ways But one thing will stay the same They will still be built to float in the water Shipbuilders will still have to understand how buoyancy and density make all ships. .. http://www.contemplator.com/sea/index.html Tall Ships Sailing Challenge http://www.cbc.ca/kids/games/tallships Water Science for Schools (U.S Geological Survey) http://ga.water.usgs.gov/edu/index.html Key Internet search terms: floating and sinking, ship, submarine, warship 31 5 Ships_ FNL.indd 31 8/11/09 4:34:59 PM Index Aircraft carriers 24, 25 Amphibious ships 24, 25 Archimedes 5 Ballast 17, 26 Bow... Stabilizers Hull Stabilizer Ships_ FNL.indd 16 Stabilizer 8/11/09 4:34:17 PM water pushes up on the fin When the fin moves up, so does the ship This stops the rightward roll Using Ballast Many ships also stay steady because weight is added to the hull This weight is called ballast Ships usually use water as ballast The water is pumped into tanks inside the hull when needed Empty cargo ships, for instance, need... (speed) 25 Load lines 22, 23 Military ships 24, 25, 26, 27 Model ships, testing with 7 Navigation equipment 21 Navy, U.S 24 Paddle wheels 19 Plimsoll, Samuel 23 Propeller (ship) 18, 19, 21 Rudder (ship) 20, 27, 28 Safety of ships 13 Shape, importance of 6, 7, 8, 14 Shipbuilding, history of 29 Sinking 10, 11, 26 Speed of ships 25 Spiny water flea 17 Stability of ships 16, 17 Steering of ship 13, 20,... parts of the world Even the heaviest cargo ships move safely from port to port How these ships are loaded is a big part of the reason Today, cargo ships have their own “load lines.” These marks are painted on the side of the hull Each mark stands for a different type of water The highest mark is TF It means tropical fresh water The lowest is W, which means winter Ships are loaded by the type of water they’re . class="bi x0 y0 w1 h1" alt="" Why Do Ships Float? by Susan Markowitz Meredith Science and Curriculum Consultant: Debra Voege, M.A., Science Curriculum Resource Teacher Ships_ FNL.indd 1 8/11/09 4:33:40. Curriculum Resource Teacher Ships_ FNL.indd 1 8/11/09 4:33:40 PM Science in the Real World: Why Do Ships Float? Copyright © 2010 by Infobase Publishing All rights reserved. No part of this book. Markowitz. Why do ships float? / by Susan Markowitz Meredith; science and curriculum consultant, Debra Voege. p. cm. — (Science in the real world) Includes index. ISBN 978-1-60413-466-7 1. Floating