Chapter 3, Lesson 2, Energy Transfer
Chapter 3, Lesson 2, Energy Transfer Slide 1 *What is the main idea? ______________ -How do moving objects transfer energy? *Energy can be transferred to one place to another __________________________________________________ -A moving object can transfer energy from one place to another. -For example, in bowling, a bowler transfers the kinetic energy of a bowling ball to the pins that the ball hits. -The bowling ball carries energy from the bowler to the pins.
Chapter 3, Lesson 2, Energy Transfer Slide 2 Transferred From Bowler To Pins
Chapter 3, Lesson 2, Energy Transfer Slide 3 *How does work transfer energy? *Work is the transfer of energy that occurs when a push or pull makes an object move. *In science, studying for a test is technically not considered work because there is no pushing or pulling involved. *Work is done only when an object moves in the same direction as the force applied to it. *Pushing on a brick wall is not work because the wall does not move. *However picking up a box is because pulling the box is causing it to move. *By doing work on the box, energy is transferred to the box.
Chapter 3, Lesson 2, Energy Transfer Slide 4 Is it considered work if you push against this wall? Why?
Chapter 3, Lesson 2, Energy Transfer Slide 5 -How do waves transfer energy? -A wave is a disturbance that transfers energy without transferring matter. -In a wavy ocean, some of the energy carried by a water wave is transferred to you as the wave moves past you. -The energy transferred by the wave causes you to move upward. -Like moving objects, waves transfer energy from one place to another.
Chapter 3, Lesson 2, Energy Transfer Slide 6 *How do water waves transfer energy? *A water wave transfers energy as it moves horizontally along the surface of the water. *Like all waves, water waves transfer energy from one place to another, but they don’t transfer matter.
Chapter 3, Lesson 2, Energy Transfer Slide 7 -How do sound waves transfer energy? -Energy can be transferred by waves that can’t be seen, such as sound waves. -Sound waves are caused by the back-and-forth movement, or vibration, of an object. -When a drummer hits a drum, the head of the drum moves back and forth many times each second. -Each time the drum head moves, it hits nearby air particles and transfers kinetic energy to them.
Chapter 3, Lesson 2, Energy Transfer Slide 8 *What are electromagnetic waves? *Electromagnetic waves are waves that can transfer energy through matter and empty space. *Electromagnetic waves are light waves that carry radiant energy. *Radiant energy moves from the Sun to Earth as electromagnetic waves.
Chapter 3, Lesson 2, Energy Transfer Slide 9 -Radio waves are used to carry signals you hear when you listen to the radio. -Microwaves are electromagnetic waves that heat food in a microwave oven. -Microwaves are also used to carry signals to cell phones. -X rays are electromagnetic waves used to diagnose broken bones. -What are types of electromagnetic waves?
Chapter 3, Lesson 2, Energy Transfer Slide 10 *What are energy conversions? -How can potential energy be converted to kinetic energy? *Energy comes in different forms and can be converted from one form to another. -When you throw a ball upward, the ball’s kinetic energy turns into potential energy when it reaches its highest point. -As the ball falls down, potential energy is converted back into kinetic energy.
Chapter 3, Lesson 2, Energy Transfer Slide 11 *How can chemical potential energy be converted? *Fuel is a material that can be burned to release energy. *Chemical potential energy is energy that is stored in the bonds between the atoms that make up wood. *When wood burns it becomes fuel because it changes from chemical potential energy into thermal and light energy.
Chapter 3, Lesson 2, Energy Transfer Slide 12 -How can thermal energy be converted to kinetic energy? -In a car, thermal energy from burning fuels can be used to perform work. -The thermal energy produced by burning gasoline causes forces to be exerted on parts of a car’s engine -These forces make various parts in the car’s engine to move making the car’s wheels move.
Chapter 3, Lesson 2, Energy Transfer Slide 13 *How can kinetic energy be converted to thermal energy? *As a car moves, some of the kinetic energy is converted into thermal energy. *The conversion of kinetic energy to thermal energy is due to friction of the moving parts in a car. *Friction is the force that resists the sliding of two surfaces in contact. *It is friction that causes a bicycle to stop when you apply the brakes.
Chapter 3, Lesson 2, Energy Transfer Slide 14 Friction
Chapter 3,Lesson 2, Energy Transfer Slide 15 -Summary -Energy can be transferred in many different ways. -Moving objects can transfer energy when they collide with other objects. -Water waves, sound waves, and electromagnetic waves can also transfer energy as they move from place to place. -Energy can can convert from one form to another.
Questions??? In science, is studying for a test considered to be work? In science, is picking up a box considered work? What kind of waves cannot be seen? What is one type of electromagnetic wave? How does a car convert chemical potential energy to kinetic energy?