1. Energy Transformations 6.14.spi.3 The student is able to recognize a variety of energy transformations.

2. Getting the Idea ENERGY is the ability to do work and comes in many forms and from many sources.

3. ENERGY comes from heat, chemicals, electricity, gasoline, and the food you eat. ENERGY cannot be destroyed, but it can be changed from one kind of energy to another.

4. Light energy can be changed into heat energy. Electrical energy can be changed into sound energy.

5. The Law of Conservation of Energy This law states that energy cannot be created of destroyed but can change from one type to another. Potential energy can be changed into kinetic energy. Every time one type of energy changes into another type, no energy is lost. The same amount of energy is there at the end as was there at the beginning. It is just in a different form.

6. Potential and Kinetic Energy Transformations MECHANICAL ENERGY is the energy an object has because of its motion or position. KINETIC ENERGY is energy of motion. POTENTIAL ENERGY is energy of position.

7. Potential energy It is energy that an object has stored and can use. It can be changed into energy of motion if a force is used to start the object moving. A watermelon resting on the roof of a building has the ability to fall downward but will not move until something pushes it. So it has potential energy but no kinetic energy.

8. As the watermelon is falling, its POTENTIAL ENERGY is being changed into energy of motion, or KINETIC ENERGY. By the time it hits the ground, it is moving pretty fast because all of its POTENTIAL ENERGY has been changed into KINETIC ENERGY. Right before it hits the ground, it has as much KINETIC ENERGY as it can have, and its POTENTIAL ENERGY is zero, since it is at the level of the ground and can’t fall farther.

9. In pieces on the ground, the watermelon has stopped moving. Now it has no POTENTIAL ENERGY because it has nowhere farther to fall. It also has no KINETIC energy because it isn’t moving anymore.

10. CHEMICAL ENERGY TRANSFORMATIONS When you turn on a flashlight, an energy transformation occurs.

11. CHEMICAL ENERGY IS THE ENERGY STORED IN THE BONDS THAT HOLD CHEMICAL COMPOUNDS TOGETHER. Batteries contain chemical energy that can be used to do work if they are connected in a circuit. When you turn the flashlight on, the batteries’ chemical energy is turned into electrical energy that moves through the flashlight wires.

12. When the electrical energy reaches the lightbulb, it is changed into light energy. Since the lightbulb gets hot, some of that electrical energy is also changed into heat energy. Energy was not created or lost. All it did was change form, from chemical energy into electrical energy into light and heat energy.

13. ELECTRICAL ENERGY TRANSFORMATIONS Your alarm goes off in the morning. You turn the light on next to your bed. At breakfast, your toast pops up out of the toaster, ready to eat. All day long, electrical energy is moving and changing into other forms of useful energy. ELECTRICAL ENERGY is energy produced by moving electric charges.

14. Think about your alarm clock. It is plugged into the wall. At a set time in the morning, it makes a loud noise. To do this, ELECTRONS FLOW OUT OF WALL SOCKET, MOVE THROUGH WIRED THROUGH THE CLOCK. Electrons give off their energy to the part of the clock that makes the sound.

15. This part changes electrical energy into sound energy. That SOUND ENERGY travels in waves through the air and into your eardrum. Good morning! Now, you follow electrical energy through a lamp. It ends as LIGHT ENERGY. Some energy is wasted as it is changed into HEAT ENERGY and makes the light bulb HOT.

16. SOLAR ENERGY It comes from sunlight. It can be transformed into electrical energy. Electromagnetic energy from sunlight is converted into electric energy to heat and cool homes and run appliances.

17. DISCUSSION QUESTION Can you think of examples from your life of the following energy transformations? A. electrical energy changed into heat energy B. potential energy changed into kinetic energy C. chemical energy changed into light energy

18. Lesson Review 1. Which energy change happens inside a lamp? A. Electrical energy turns into chemical energy. A. Electrical energy turns into chemical energy. B. Light energy turns into electrical energy. B. Light energy turns into electrical energy. C. Electrical energy turns into nuclear energy. C. Electrical energy turns into nuclear energy. D. Electrical energy turns into light energy. D. Electrical energy turns into light energy.

19. 2. You climb to the top of a hill to take a look at the view. Which energy transformation occurred during your climb? A. potential energy turned into kinetic energy A. potential energy turned into kinetic energy B. potential energy turned into chemical energy B. potential energy turned into chemical energy C. kinetic energy turned into potential energy C. kinetic energy turned into potential energy D. kinetic energy turned into light energy D. kinetic energy turned into light energy

20. 3. What cannot happen, according to the law of conservation of energy? A. Energy can change form. A. Energy can change form. B. Energy can be destroyed. B. Energy can be destroyed. C. Energy can be changed from chemical to heat. C. Energy can be changed from chemical to heat. D. Energy can be useful. D. Energy can be useful.

21. 4. Which kind of energy does a battery have? A. chemical A. chemical B. potential B. potential C. kinetic C. kinetic D. electrical D. electrical