What you need to know about heat. Some materials conduct heat better than others A thermal conductor (heat conductor) is a material that conducts heat well and quickly. Metals are good thermal conductors. A thermal insulator (heat insulator) is a material that does not conduct heat well. Plastics, wood, cork and some fabrics are good thermal insulators.
Gravity <ul><li>An object has a mass, which is the total amount of material it is made of. Mass is not a force and is measured in Kilograms. </li></ul><ul><li>We measure forces in Newtons using a Force meter (also called a Newton meter). </li></ul><ul><li>The force that attracts or pulls the earth and an object (such as a person) towards each other is called gravity. </li></ul><ul><li>The pull on the mass of any object by the planet makes the force that we call weight. </li></ul><ul><li>Other planets, stars or moons also have gravity . </li></ul>
Friction <ul><li>Friction is a contact force between materials. </li></ul><ul><li>When we try to move an object, the force preventing or slowing that movement is called friction. </li></ul><ul><li>If the object is already moving, the force slowing down the object is called friction, so friction is a push against a moving object. </li></ul><ul><li>Friction can be a useful force because it prevents our shoes slipping on the road when we walk and stops car tires sliding. </li></ul><ul><li>Air resistance is a type of friction between air and another material. </li></ul>
Metric Weights and Measures <ul><li>Moat of the world uses the metric system. The only countries not on this system are the U.S., Myanmar, and Liberia. </li></ul><ul><li>The metric system is based on 10s. For example, 10 decimeters make a meter (39.37 inches). </li></ul>
Units smaller than a meter have Latin prefixes: Deci means 10; 10 decimeters make a meter. Centi means 100; 100 centimeters make a meter. Milli means 1,000; 1,000 millimeters make a meter. Units larger than a meter have Greek prefixes: DeKa means 10; a dekameter is 10 meters. Hecto means 100; a hectometer is 100 meters. Kilo means 1,000; a kilometer is 1,000 meters.
The Metric System Length 0.001 Meters Millimeter (mm) 0.01 Meters Centimeter (cm) 0.1 Meter Decimeter (dm) 1 Meter Meter (m) 10 Meters Dekameter (dam) 100 Meters Hectometer (hm) 1,000 Meters Kilometer (km) Value Unit