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Kineticenergy istransferredto grassA moving soccer player haskinetic energy.Kinetic energy from the player’s moving legis transferred to the ball.When the ball rolls, its kineticenergy is transformed by frictioninto heat as the ball rubs againstthe grass.Following the Energy Trail The flow of energy as a soccerball is kicked is shown in Figure 10. Chemical energy in the soccerplayer’s leg muscles is converted into kinetic energy whenshe swings her leg. When the ball is kicked, this kinetic energy istransferred to the ball. After the ball rolls for a while, it comes toa stop. The kinetic energy of the ball seems to have disappeared,but it hasn’t. As the ball rolled, its kinetic energy was transformedinto heat energy as the ball rubbed against the grass.Figure 10 Energy can take differentforms, but it can never becreated or destroyed.SummaryEnergy•Energy is the ability to cause change.Energy has different forms such as chemicalenergy, nuclear energy, heat energy, and•electrical energy.Energy can be transformed from one forminto another.•Kinetic and Potential EnergyKinetic energy is the energy due to themotion of an object and increases as the•object’s mass or speed increases.Potential energy is stored energy due to anobject’s position and increases as the object’sheight above Earth increases.•Law of Conservation of EnergyThe law of conservation of energy states thatenergy cannot be created or destroyed, butonly transformed from one form into another.Self Check1. Describe the energy transformations that occur when alight bulb is turned on.2. Explain how the total energy changes when a fallingrock hits the ground.3. Infer on which part of a roller coaster a roller coastercar has the greatest potential energy.4. Determine which has the greater kinetic energy if bothare traveling at the same speed—a fully-loaded truckor a motorcycle.5. Think Critically When a ball is thrown upward, howdoes the height reached by the ball depend on itsinitial speed?6. Diagram the energy transformations that occur whenyou eat breakfast, walk to the bus stop, and ride thebus to school.red.msscience.com/self_check_quizSECTION 1 Energy Changes 169(l)Jim Cummins/FPG/Getty Images, (c)Jim Cummins/FPG/Getty Images, (r)David Young-Wolff/PhotoEdit, Inc.