Energy Transfer Notes Energy- Energy is the ability to do work or cause a change. Energy can be exchanged or transferred from one form to another, but it never goes away. Investigation 1 – What happens to the light when it strikes the different colored balloons? The black balloon became hotter than the white balloon because more light energy was absorbed into the darker color and reflected off the lighter color. Light energy transfers in heat energy. Investigation 2 – How is heat produced? Heat energy can change the temperature of objects, change matter from one state to another, and move one object to another by conduction. Heat energy, due to friction, is produced when you rub your hands together. The temperature of your hands increase due to rubbing/friction. The temperature decreases when you stop rubbing after awhile. Know how heat energy is transferred from a candle to a beaker of water. Heat energy is produced when substances burn, when certain kinds of materials rub against each other, and when electricity flows through wires. Different kinds of energy: Heat energy, light energy, electrical energy, chemical energy, solar energy, mechanical energy, sound energy. Investigation 3 – What happens to the temperature when a hot substance and a cold substance are combined? The addition of ice to hot water resulted in a liquid with a cooler temperature than the hot water before the ice. Look at the data in your science journal. The addition of the ice did not cool the beverage as the heat energy transferred from the hot water to the cold ice. Heat transfer moves from the warmer substance or object to the colder substance or object. The heat energy in the hot water transferred to the ice, as the ice melted the temperature of the hot water and melted iced became the same temperature. Investigation 4 – What changes can be observed as a result of electricity? There are 2 types of electricity: static and current electricity. Static Electricity – Static electricity occurs when conditions are just right for charges in the air to line up and cause an attraction. It causes an attraction between objects. It can cause a small shock. Static Electricity is not the form of electricity that runs appliances. Current Electricity - Is converted to heat (hair dryer) or mechanical energy ( radio, fan, cd player) or light (lamp) or Magnetism (Computers, TV) Lightning is an example of a grand display of electrical energy in nature. Investigation 5 – How do you light a light bulb? The students learned that the metal tip of the bulb or the side of the metal bulb base must touch one end of the battery. Then a wire must touch the other part of the bulb (base or tip) and other end of the battery for the bulb to light. This is a simple electric circuit. Investigation 6 – What is necessary to have an electrical circuit? Source – pushes electricity along the circuit (examples: battery, generator), path – the path carries the electricity between the source and the load and back. (copper wires) Load- part of the circuit that uses the electricity to make light, heat, sound or produce movement or magnetism. Investigation 7 – What types of materials are good/poor conductors of electricity? A conductor – A conductor is a material that allows electricity to flow through it. Metals are examples of good conductors. Investigation 8 – How can a switch open and close an electrical circuit? A switch in an electrical apparatus can open and close an electrical circuit. If the switch is open, the electric current stops moving and the circuit is broken. When the switch is closed, the electric current moves and the circuit is complete. An electric circuit must be complete for electricity to move through it. If the circuit is broken, the electric current will not move. A circuit that is broken or incomplete is called and open circuit. An open circuit means that there is a gap or opening somewhere between the source, path, and/or load. You may also use your science journal to review for the test. Look over each lesson and conclusion. Also, review the vocabulary in the back of the science journal.