Energy II
Science ‐ Middle 1st Grade St. George's College November, 2008 1
Brainstorming: What is Warm and Cold?
contains attracts
repulses vibrates transmits work
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Middle 1st Grade ‐ Energy II Name
Oral Intervention
Coin
Chocolate
Name
Marcelo
Alfredo
Antonella
Giuliana
Paulo
Joshua
Sergio
Kinley
Maria Fernanda
Arianne
Alejandro
Maria Gracia
Alejandra
Sandra
Brenda
Fiorella
Hettore
Gonzalo N.
Almendra
Rodrigo
Diego
Paolo
Anna Paula
Gonzalo R.
Gabriel
Giorgio
Sandra
Jaime
Maia
Steffano
Valeria
Bruno
Cristina
Maria Claudia
Oral Intervention
Coin
Chocolate
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Objectives • investigate the transfer of thermal energy through different materials. • Describe thermal energy and explain conduction, convection, and radiation. • Describe how insulation works. • Define current electricity as a flow of electrons and describe how electricity is produced. • Define a circuit and distinguish between series and parallel circuits. • Describe how an electromagnet works. Note: Most of the objectives will be covered in class, however the student must be responsible for those objectives not covered or concluded. 4
Vocabulary
• Thermal Energy: the kinetic energy of the moving particle of a substance of an object. • Heat: the transfer of thermal energy from warmer objects to cooler ones. • Conduction: the transfer of thermal energy that results from the collision of particles. • Convection: the transfer of thermal energy through the movement of a liquid or a gas. • Radiation: the transfer of thermal energy as waves. • Insulation: a substance that conducts thermal energy poorly. • Static Electricity: the electric charge that builds up on an object that has gained or lost electrons. • Current Electricity: the flow of electric charges through a wire. • Circuit: a continuous path through which electric charges flow. • Series circuit: a circuit in which there is only one path for the current to flow. • Parallel circuit: a circuit in which there is more than one path for the current to flow. • Electromagnet: a temporary magnet that is made by passing an electric current through a coil of wire that surrounds an iron core. Note: Most of the vocabulary words will be covered in class, however the student must be responsible for those words not covered or concluded.
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Lesson 1: How is Thermal Energy transferred?
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Thermal Energy
Assignment
• The kinetic energy of the moving particles of a substance or object is called thermal energy. • The more thermal energy an object or substance has, the warmer it is. • To find out how warm an object is, a thermometer is used. • Temperature is a measure of the average kinetic energy of the particles in an object or a substance. The faster the particles move on average, the higher the temperature is. • Temperature is measured in scales. • The amount of thermal energy in an object is related to its mass.
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Heat: Thermal Energy on the Move • Heat is the transfer of thermal energy from warmer objects to cooler ones. • Three processes transfer thermal energy. • Conduction is the transfer of thermal energy that results from the collision of particles. How about solids, liquids and gases? • Conduction transfers heat only from the warmer object to the cooler object. • Convection is the transfer of thermal energy through a fluid. That fluid may be a liquid or a gas. • Convection happens because of temperature differences in different parts of the fluid. It's a matter of density. • Radiation is the transfer of energy as waves.The most familiar source of radiant energy is the Sun.
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Insulation • Insulation is a substance that conducts thermal energy poorly. • How do people use insulation?
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Lesson 2: What is Electricity and how is it produced? 11
Static Electricity • An atom has positively charged protons in the nucleus and negatively charged electrons in the outer level of energy. It's possible to remove some electrons from atoms, leaving them positively charged. • The electrons can move to another object, making it negatively charged. • Since opposite charges attract, the two objects come together. • The electric charge that builds up on an object that has gained or lost electrons is static electricity.
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Current Electricity • Current electricity is the flow of electric charge through a wire. • Most materials that are good conductors of thermal energy also conduct electricity well. • Materials that are poor conductors of thermal energy and electricity are insulators.
Electricity Animation
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How Electricity is produced • Electricity is just one form of energy, it can't be made from nothing but most be produced from some other form of energy. • At a hydroelectric plant, the energy comes from falling water (potential energy).
Electricity Animation
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More sources of energy to generate Electricity • Electricity can be generated from many sources of energy, such as: Solar, wind, geothermal, nuclear, burning fossil fuels, etc.
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Peru Our country almost all its electric energy from 2 sources: Hydroelectric plants and Thermal processes.
Electric energy consumption per person 1995‐2007
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Lesson 3: What is a Circuit?
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Circuits • A circuit is a continuous path through which charge flows. If a circuit is open in even one place, the flow of electric charge stops. • Batteries are sources of electric charge. A battery has two ends marked (+), or positive, and (‐), or negative. • These are the terminals of the battery. Inside it, a chemical reaction separates charges. • Electrons building up on one end, giving it a negative charge. The other terminal has fewer electrons, so it has a positive charge. When a wire connects the battery's negative terminal to its positive terminal, charges flow from the negative terminal to the positive terminal. • A switch controls a circuit. A switch in the off position opens the circuit, and charges don't move. A switch in the on position completes the circuit, and electric charge flows along the wires.
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Types of Circuits • In a series circuit there is only one path for the current to follow. Current can move through one, two or more devices, but it must pass through one in order to get to the next. • The devices in the circuits are called resistors. Resistors resist the flow of charges. • In a parallel circuit devices are connected along separate paths, and current doesn't have to pass through one device to get to the next. • If something stops electrons from moving along one path, they can take another path. This gives a parallel circuit some advantages over a series circuit. It's easier to repair, if one device stops working, it's easy to know which one needs to be replaced. • With a series circuit, all the devices must be tested to find a single damaged one. • In addition, parallel circuits can have separate switches in them, individual switches can turn off one device while other devices on the same circuit continue to work.
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Using Electric Current • People use electric current in many ways. • An electromagnet is a temporary magnet made by passing an electric current through a coil of wire that surrounds an iron core. • When the circuit is closed, the electromagnet attracts objects that contain iron, steel or nickel. • An electromagnet works because flowing through a coil produces a magnetic field. • When current runs through a coil of wire, the magnetic field is strongest inside the coil. he field causes any iron‐containing object inside the core to become temporarily magnetic.
Optional Assignment Make an electromagnet to be used in the lab.
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Assignment • Find the temperature scales, and what is the scale based on. • Write your assignment in your notebook for Wednesday 19th, 2008.
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