Energy Transformations 5.2 Part 1

Forms of Energy Potential (stored) Kinetic (motion) Gravitational potential Elastic potential Chemical potential Mechanical Thermal (heat) Radiant (light) Electric Sound Nuclear

Law of Conservation of Energy Energy can not be created or destroyed, it can only be transformed (changed) or transferred to another location. A change from one form of energy to another is called an energy transformation.

the total amount of energy is the same before and after any transformation. If you add up all the new forms of energy after a transformation, all of the original energy will be accounted for.

Potential and Kinetic Transformation One of the most common energy transformations is the transformation between potential energy and kinetic energy. Example: The water at the top of the falls has gravitational potential energy. As the water plunges, its potential energy becomes kinetic energy.

Energy Transformation in Juggling Any object that rises or falls experiences a change in its kinetic and potential energy. When it moves, the orange has kinetic energy. As it rises, it slows down. Its potential energy increases as its kinetic energy decreases.

Energy Transformation in Juggling At the highest point in its path, it stops moving. it has the highest gravitational potential energy. As the orange falls, the energy transformation is reversed. Kinetic energy increases while potential energy decreases.

Potential energy is converted into kinetic energy. Before the yo-yo begins its fall it has maximum stored energy due to its position. As it starts to fall the potential energy begins to be changed into kinetic energy. At the bottom the kinetic energy is at its maximum

Let it Roll Lab Height of the ramp (cm) Distance of the marble (cm) Trial 1 Trial 2 Trial 3 Trial 4 Trial 5

Tracking Energy Transformations Because of friction, the mechanical parts of the bicycle are warmer, too. Thermal energy is almost always produced by an energy transformation. The energy transformations that occur when people exercise, when cars run, when living things grow and even when stars explode, all produce thermal energy.

Other Energy Transformations Friction is the force that resists the sliding of two objects that are touching. It causes thermal energy or waste energy to be released. Waste energy is always given off, but is not needed

Examples of Friction

chemical energy stored in food transforms to mechanical energy (move) and thermal energy maintain body temperature

A radio transforms electrical energy to sound plus thermal energy (waste) Chemical energy is transformed to mechanical energy to sound energy plus thermal energy (waste)

Electrical energy is transported to your house through power lines. When you plug an electric fan to a power outlet, electrical energy is transform into mechanical energy Chemical from the match transforms to Radiant plus sound energy