Where did this energy come from? ACTIVITY #6: Where’s the Energy Going? Using Energy Transfer and Transformation to Follow Changes in the World Around Us   In this investigation, you will attempt to trace the flow of energy in everyday phenomena. Whenever any change takes place in the world around us, an exchange of energy is usually part of that change. Sometimes the energy is transferred between objects; sometimes it also undergoes transformations into different forms. Keeping track of role that energy plays in these changes often helps us understand why the changes take place and make predictions about what the changes will be like. To keep track of the ‘flow’ of energy, we create ‘energy chains’. An energy chain is a description of how the energy is passed along from one object to another, and what transformations take place in the process. Take for example the energy chain of a kicked football. It starts with the food energy inside the kicker, which is transformed into the kinetic energy of his leg and foot. This kinetic energy is then transferred to the football. As the ball climbs on its path through the air, part of its kinetic energy is transformed to gravitational potential energy, and the chain goes on. An example of how energy chains can help us understand an event … imagine yourself running up to a football, preparing to kick it, but for some reason, your kicking foot misses the ball. If this has happened to you, you know that what follows is embarrassing, if not painful. Energy chains can be used to explain why it is so difficult to maintain your balance and so easy to ‘pull’ a muscle in your leg when you miss a football. Whenever we observe an event-taking place (or study one that has already taken place), we can better understand what is happening by asking questions about what happened to the energy during the event. Where did this energy come from? How far back can you trace the sources of the energy?

GOALS: In this lab activity, you will … ·        Identify different forms of energy and how these energy forms are transferred and undergo transformations in everyday phenomena. ·        Construct an energy chain that describes the energy flow in everyday phenomena. ·        Use the Particle Model and the concept of energy transfer to describe how air particles interfere with the motion of objects. Activity Overview: A synopsis of this lesson is as follows… This is an opportunity to use the concepts of energy transformation (from one energy form to another) and energy transfer (from one object to another object) to trace the role of energy flow in any physical process. You will be given examples and asked to trace the flow of energy using energy chains.

(MOST ENERGY ENDS UP IN THE GRAVE YARD!!—HEAT ENERGY) MAKE ENERGY CHAINS   §         Describing energy flow that allowed you to get from your house to school. §         Describing the energy flow that enables you to walk down the hallway at school. §         Describe the energy flow that allows the custodian to raise the flag up the flagpole in the morning. §         Describe the energy flow that allows a coffee pot to produce a warm cup of coffee in the morning. (MOST ENERGY ENDS UP IN THE GRAVE YARD!!—HEAT ENERGY)

Energy can be transferred from one object to another. Energy can exist in different forms. ·         Sometimes the energy of an object is easily detectable, for example, the energy it has because of its motion (kinetic energy). ·         Sometimes the energy of an object is more difficult to detect because it is a stored energy (for example, the gravitational potential energy). ·        Energy can be transferred from one object to another.          When one object pushes or pulls on another object often (but not always) energy is transferred from one of the objects to the other. As a result of this transfer, the motion of one or both of the objects will change. When kinetic energy is transferred to a large stationary solid this energy is transferred to the particles that make up the object. The kinetic energy may take the form of organized vibrations within the solid (a mechanical wave), but will ultimately become the random vibrational kinetic energy of the particles. This collective random kinetic energy of the particles is called heat energy.

Energy can be transformed from one form to another Energy can be transformed from one form to another. This process is called the transformation of energy. ·         When an object is lifted, energy needed to lift it up is transferred to the lifted object, and transformed into gravitational potential energy. ·         If an object is thrown upward, its kinetic energy is transformed into potential energy. The object’s potential energy increases as it travels higher, and the object slows down as its kinetic energy decreases. ·         When an object falls or rolls down a ramp, gravitational potential energy is transformed into kinetic energy. As a result of this transformation, the object’s kinetic energy increases, and the object’s downward motion speeds up. In most cases, the kinetic energy of objects in motion eventually becomes the random kinetic energy of the particles that make up the object. We call this form of energy heat energy. By understanding energy transformation and energy transfer, we can begin to understand that the energy of an object can change forms and be passed to other objects but cannot be either created or destroyed.

Let’s View the ESPN Sports Figures “Boarding School” Video   ENERGY CHAINS We begin our Energy Chain investigation by reviewing some of the previous material and seeing just how all of it fits together. We will accomplish this task with the help of ESPN and skateboarding star Tony Hawk by watching the Sports Figures program entitled “Boarding School”.   REVIEW QUESTIONS …. Let’s View the ESPN Sports Figures “Boarding School” Video What types (forms) of energy are discussed in the video?   Compare Tony Hawk’s trips back-and-forth on the half pipe to the swinging pendulum (soda bottle) from Activity #4.   In one scene a bowling ball is released from the top and eventually it comes to a stop at the bottom of the half pipe. Where did the energy go?  

What is an energy chain?   In our everyday life, energy is transferred and transformed continuously. It is helpful to be able to track the ‘flow’ of energy throughout our everyday life. A map of what happened to the energy, where did it go, and how did it change, is called an ENERGY CHAIN. A good example of an energy chain is an automobile’s use of its input energy. How much of the energy in the gasoline actually becomes kinetic energy of the car? The answer is a staggeringly small 12% ! So where does the energy go if not into the kinetic energy of the car? ü      How many forms of the ‘wasted’ or ‘discarded’ energy can you identify?  ü      Describe the transfer and transformations that took place that leads to the formation of these forms of ‘wasted’ energy. 

Investigating Further …   What is the earth’s main source of energy? The SUN is our primary source of energy for the earth. About 99% of the energy used on the earth stems from the sun. It provides the energy to power the weather patterns and affects our home planet’s position in the solar system. Can you trace the flow of energy backwards from you reading this page to the sun?

In your journal or notebook, write a concise summary of this activity. Summary of Activity …   In your journal or notebook, write a concise summary of this activity. Be sure to address the following questions and use your data to support your responses. ü      How can energy change forms? ü      How can energy be passes from one object to another object? ü      How can an energy chain can be useful in our everyday life? ü      Can energy ever be “lost”?