Forms of Energy
Science ‐ Middle 6th Grade St. George's College November, 2008 1
Middle 6th A ‐ Forms of Energy Name
Ariana Abraham Fabiana Liliam Francesca Luis Luciana Andres Valeria Stefano Diego Camila G. Ramiro Sara Alicia Ivanna Camila M. Aaron Paola Luis Fernando Enrique Sebastian Irma Naomi Kiara
Brainstorming: What are the forms of Energy?
Middle 6th B ‐ Forms of Energy Name
Nicole Andrea Sinead Rodrigo C. Antonella Valeria Jean Pierre Analucia Rodrigo H. Luis Franco Sergio Giancarlo Fiorella Gabriela Alonso Steffano Diego Alessandra Julio Sherley Sophia Vilma Christopher
Brainstorming: What are the forms of Energy?
Objectives • Describe Potential and Kinetic energy. • Describe the various forms of energy. • Explain electric energy and electric current. • Describe how electromagnets work. • Describe the characteristics of light energy and sound energy. • Identify and compare the characteristics of light waves and sound waves. • Describe thermal energy and how it moves. • Describe chemical energy.
Note: Most of the objectives will be covered in class, however the student must be responsible for those objectives not covered or concluded.
Vocabulary Energy: the ability to cause change in matter. Kinetic Energy: the energy of motion, or energy in use. Potential Energy: the energy an object has because of its place or condition. Electric Charge: the charge obtained by an object when it gains or loses electrons. Electric Force: the attraction or repulsion of objects due to their charges. Electric Current: the flow of electrons from negatively charged to positively charged objects. Conductor: a material that conducts electrons easily. Electric Circuit: the path along which electrons can flow. Insulator: a material that does not carry electrons. Resistor: a material that resists the flow of electrons in some way. Electromagnet: a temporary magnet made by passing electric current through a wire coiled around an iron bar. Reflection: the light energy that bounces off objects. Refraction: the bending of light rays when they pass through a substance. Lens: piece of clear material that bends, or refracts, light rays passing throue gh it. Pitch: an element of sound determined by the speed at which sound waves move. Volume: the amount of space that an object takes up; [sound], the loudness of a sound. Temperature: the average kinetic energy of all the molecules in an object. Heat: the transfer of thermal energy from one substance to another. Conduction: the direct transfer of heat between objects that touch. Convection: the transfer of heat as a result of the mixing of a liquid or a gas. Radiation: the transfer of thermal energy by electromagnetic waves.
Note: Most of the vocabulary words will be covered in class, however the student must be responsible for those words not covered or concluded. 7
Lesson 1: What are the forms of Energy?
Kinetic and Potential Energy • Energy is the ability to cause changes in matter. • There are two basic kinds of energy: the energy of motion, or energy in use, is kinetic energy. Any matter in motion has kinetic energy. • Potential energy is the energy an object has because of where it is or because of its condition. • The change of any object's energy back and forth between kinetic energy and potential energy is called the transformation of energy. • Although energy often is transformed, or changed, from one form to another, the total amount of energy doesn't change. • Energy can't be created or destroyed. This is the Law of Conservation of Energy.
Forms of Energy • The kinetic energy that moving objects have is also called mechanical energy. • Thermal energy is another form of kinetic energy. The movement of molecules of matter is thermal energy. • Electric energy, another form of kinetic energy, is caused by the movement of electrons. • Light energy from this screen moves to your eyes in waves. • Your ears can receive vibrations produced by tv, or radio speakers as sound energy. • potential energy also takes several forms: Elastic potential energy is the energy stored in uncompressed springs, stretched rubber bands, etc. • Gravitational potential energy is the energy an object has when it's in an elevated position. • Other form of potential energy is: chemical energy.
Lesson 2: What is Electric Energy?
Electric Charges • Electric energy is produced by the movement of electrons. • Within an atom, electrons have a negative charge and protons have a positive charge. So the two types of particles attract each other. • When an object gains or loses electrons, it has an electric charge. • An object that has gained electrons has a negative electric charge due to the excess of electrons. • An object that has lost electrons has a positive electric charge due to the deficiency of electrons.
Electric Force • Most objects have no charge because they have the same numbers of protons and electrons. • If an object has a charge, it attracts objects with the opposite charge, similar to magnetic forces. • This attraction or repulsion is called electric force. • Charged objects have potential electric energy, or static electricity, because the electrons aren't moving. • Electrons flow from negatively charged objects to positively charged objects. • The flow of electrons is called electric current. • Once electrons have moved from one object to the other, the attraction between the objects is gone. The charges are balanced and there is no electric force.
Electric Current • Unlike static electricity, an electric current is the flow of electrons. • In dry cells or batteries, chemical reactions build up opposite charges, forming poles or terminals (positive and negative). • Electrons are attracted from one terminal to the other. Connecting the two terminals allows an electric current to flow between them. • Electric current flows through many kinds of matter if the electric force is strong enough. • But some kinds of matter conduct, or carry, electrons more easily than others. • A material that conducts electrons easily is called a conductor.
Electric Circuits • An electric circuit is any path along which electrons can flow. • Metals are good conductors of electric current because their atoms don't hold electrons tightly. This allows electrons to move along from one atom to the next. • An electric current flows through good conductors with little resistance. • The conductor in a circuit is wrapped with a material called an insulator, which is a material that doesn't carry electrons. Insulation keep wires from touching each other and avoiding a short circuit. • Some materials are neither conductors nor insulators. However, they resist the flow of electrons in some way. These materials are called resistors. Materials that resist electric current are important because they allow electric energy to be changed into other forms.
Magnets and Electricity • Magnets are used to generate, or produce, electricity. Spinning a coil of wire inside a magnetic field produces an electric force between the ends of the coil. • In a similar way electric current produces a magnetic field around it. • A coil wrapped an iron bar becomes a magnet only when electric current flows through the coil. For this reason it is called an electromagnet. • this link between electricity and magnetism allows motion to be produced from electric energy.