(6.9)Science concepts. The student knows that obtaining, transforming, and distributing energy affects the environment. The student is expected to: (A) identify energy transformations occurring during the production of energy for human use such as electrical energy to heat energy or heat energy to electrical energy; Verb: Identify Noun: energy transformations Context: During the production of energy for human use Vocabulary: energy transformations Identify: to recognize or establish as being a particular person or thing: verify the identity of.

The Law of Conservation of Energy Energy can be found in a number of different forms. It can be chemical energy, electrical energy, heat (thermal energy), light (radiant energy), mechanical energy (kinetic energy), and nuclear energy. The Law of Conservation of Energy Energy is converted from one form to another, but it is never created or destroyed.

Energy transformation is the change in energy form. Nuclear energy is converted to mechanical energy and then into electrical energy in a nuclear power plant. Gasoline, chemical energy, is converted to heat energy & mechanical energy by a car.

Before bouncing Mechanical energy is converted into thermal energy when you bounce a ball After bouncing

Chemical Energy  Heat & light energy What kind of energy transformations are shown in the following pictures? Solar energy (light energy)  Chemical Energy Chemical energy  Mechanical Energy Solar Cell Wind energy  Mechanical Energy Solar energy (light energy)  Electrical Energy

Diesel fuel is used in the engines of the machines and trucks at the quarry. Which of these is the main energy transformation as the fuel is used by the engines? A Electrical energy is converted to heat energy. B Heat energy is converted to potential energy. C Electrical energy is converted to kinetic energy. D Chemical energy is converted to kinetic energy. Identify what the question is asking. What other information does the question give you? What energy does this represent? What is the best answer?

Which of the following can be used to transform chemical energy into heat energy? A. A windmill turning Answer: B B. lighting a match C. solar panels D. a light bulb

Which of these types of energy conversions occurs in a battery-powered flashlight? A. Thermal to mechanical B. Light to electrical C. Thermal to chemical D. Chemical to electrical Answer: D

Potential & Kinetic Energy Potential Energy is the energy that is stored because of an object’s position or shape. The energy of an object due to its motion is called Kinetic Energy. (also called mechanical energy!)

EXAMPLE 1 Potential Energy POSITION 1 (resting) Potential Energy The boulder at the top of the hill has potential energy and no kinetic energy. Then… POSITION 2 (moving) Kinetic Energy As the boulder rolls down the hill, the potential energy transforms into kinetic energy and kinetic energy becomes greater until… POSITION 3 (resting) Potential Energy The boulder is in a resting position with low potential energy and no kinetic energy.

EXAMPLE 2 When a student rides a bike down a hill, potential energy is transferred into kinetic energy. Potential Energy (at rest) Kinetic Energy (moving)

The amount of kinetic energy also depends on the mass and the speed of an object. Kinetic energy increases as speed increases. The faster an object moves, the more kinetic energy it has. EXAMPLE 3: The faster a bowling ball moves, the harder it will strike the pins, the more pins it can knock down.

Explain how energy is transformed as the ball rises and falls. As the ball leaves the ground, it is moving the fastest and has the maximum kinetic energy. As the ball moves upward, it slows down as it’s kinetic energy is transformed into potential energy. As the ball moves downward, it speeds up as its potential energy is transformed into kinetic energy. 2 EXAMPLE 4 Explain how energy is transformed as the ball rises and falls. 1 3

The boulder would have the greatest kinetic energy at which of the positions on the waterfall? 1 2 3 4 A position 1 B position 2 C position 3 D position 4 B B ; position 2

A yo-yo can demonstrate both Potential and Kinetic energy A yo-yo can demonstrate both Potential and Kinetic energy. When does a yo-yo have it greatest potential energy? A In the hand before the yo-yo is released B At the bottom of the string C When the yo-yo is falling D When the yo-yo is climbing the string A In the hand before the yo-yo is released.

Which will have the most kinetic energy rolling down the hill? A Truck B Ball C Runner D All of the are examples of Potential energy. Answer: A