ENERGY Bill Nye Energy https://www.youtube.com/watch?v=C4pnVGko0zU - - PowerPoint PPT Presentation
ENERGY Bill Nye Energy https://www.youtube.com/watch?v=C4pnVGko0zU What are kinetic and potential energy? CHAPTER 15 LESSON 1 Chapter Introduction pages 554-557 Write Vocab terms page 557 #1-5 Do the Investigate with a
Bill Nye Energy https://www.youtube.com/watch?v=C4pnVGko0zU
What are kinetic and potential energy?
pages 554-557
page 557 #1-5
a partner pgs 558-559
ENERGY VOCABULARY CHAP15 LESSON 1
Energy - the ability to cause change in matter or do work Kinetic Energy - energy of motion Potential Energy - energy an object has because of its condition or position Energy transfer – movement of energy from one place or object to another Law of conservation of energy – energy can never be made or destroyed but it can change form
THE LAW OF CONSERVATION OF ENERGY
THE LAW OF CONSERVATION OF ENERGY
Potential energy is converted to kinetic then to mechanical
POTENTIAL ENERGY => KINETIC ENERGY => MECHANICAL ENERGY
THE LAW OF CONSERVATION OF ENERGY
Sunlight (heat) is used by plants for Photosynthesis (to make food). It is converted to chemical energy.
HEAT ENERGY => CHEMICAL ENERGY
THE LAW OF CONSERVATION OF ENERGY
Oil and gas are burned in power stations to produce heat energy. It is used to turn turbines which produce electricity (electrical energy) HEAT ENERGY => ELECTRICAL ENERGY
In an automobile engine, fuel is burned to convert chemical energy into heat energy. The heat energy is then changed into mechanical energy.
THE LAW OF CONSERVATION OF ENERGY
CHEMICAL ENERGY => MECHANICAL ENERGY
Kinetic Energy energy of motion Potential Energy Stored energy
https://www.youtube.com/watch?v=BWiYah08buI
POTENTIAL ENERGY
has
waiting to happen.
KINETIC ENERGY
moves, the more kinetic energy it has.
moving object, the more kinetic energy it has.
both mass and velocity.
ENERGY VOCABULARY CHAP 15 LESSON 2 page 570-574
Solar Energy - energy from the sun. Light Energy - energy in the movement of light particles Chemical energy – energy that is released by a chemical reaction (burning) Mechanical energy – combination of all the kinetic and potential energy that something has Electrical Energy - energy that flows through a circuit Nuclear Energy – energy that is released during nuclear fission to generate electricity
FORMS OF ENERGY
The five main forms of energy are:
Heat Chemical Electromagnetic Nuclear Mechanical
HEAT ENERGY
✓ Heat is a form of energy created by the movement of molecules ▪ substances change form when heated (solids, liquids, and gases) ✓ Heat energy can be produced by friction. ✓ If an object becomes hotter, it has gained heat energy.
➢ Chemical Energy is required to bond atoms together. ➢ When chemical bonds are broken, energy is released. ➢ Fuel and food are forms of stored chemical energy.
➢ When work is done to an object, it acquires energy. ➢ When you kick a football, you give mechanical energy to the football to make it move. ➢ When you throw a bowling ball, you give it energy, then energy is transferred through momentum.
ELECTROMAGNETIC ENERGY
➢ *EM waves can carry energy through places with or without any matter. ➢ *The Sun is the main source of EM energy on Earth. Part of this energy, light, is used by producers to make food. ➢ energy ➢ EM is carried by X-rays, radio waves, (R O Y G B I V) 22
➢ The nucleus of an atom is the source
➢ When the nucleus splits (fission), nuclear energy is released in the form
light energy. ➢ Nuclear energy is the most concentrated form of energy.
ENERGY VOCABULARY CHAP15 LESSON 3
Heat – transfer of thermal energy between objects with different temperatures Conduction - transfer of heat from one object Directly to another Convection – transfer of heat through the movement of a gas or liquid Radiation – transfer of heat from one place to another through light, sound, heat, or x-rays Reflection – bouncing of heat or light off an object
ENERGY VOCABULARY CHAP15 LESSON 3 Electromagnetic waves - waves of energy and light moving around us in many forms (solar, TV, radio, gamma, x-ray, heat) Conductor - materials that electricity or heat can easily flow through Insulators - materials that electricity or heat cannot easily flow through
❖ Heat always moves from a warmer place to a cooler place. ■ Hot objects in a cooler room will cool to room
■ Cold objects in a warmer room will heat up to the room temperature. (butter, ice)
❖ HOT objects expand, COLD objects contract ➢ Bridges expand on hot days and contract on cold days ➢ Wood expands when heated then contracts when cooled ❖ If an object: ➢ cools down, it means it has lost energy. ➢ If an object becomes hotter, it has gained heat energy.
Heat transfers in three ways:
ConDuction is Direct contact, for example:
✓ warming your hands on a coffee mug ✓ cooking on a stove ✓ candy melting in your hands When you heat a metal strip at one end, the heat travels to the other end. As you heat the metal, the particles vibrate, these vibrations make the adjacent particles vibrate, and so on and so on. The vibrations are passed along the metal and so is the heat.
➢ It is the way in which particles in a GAS or
LIQUID move upwards, carrying heat with them
➢ Think about when you boil water, the
bubbles move upwards
➢ Or think of a gas heater in the room,
the heat rises around the room
Cooler water sinks Cools at the surface Hot water rises Convection current
Cooler, more d____, fluids sink through w_____, less dense fluids. In effect, warmer liquids and gases r___ up. Cooler liquids and gases s___. ense armer ise ink
✓ Convection in the
atmosphere helps to move thermal energy around the Earth.
✓ Hot air rises and
cool air falls, causing a circular motion to create wind!
CONVECTION: ATMOSPHERE
people’s homes? Hot water rises. So when the boiler heats the water, and the hot water rises, the water tank is filled with hot water.
Cool air is more dense than warm air, so the cool air ‘falls through’ the warm air.
How does heat energy get from the Sun to the Earth? There are no particles between the Sun and the Earth so it CANNOT travel by conduction or by convection.
body
Why are houses painted white in hot countries? White reflects heat radiation and keeps the house cooler. Why are shiny foil blankets wrapped around marathon runners at the end of a race? The shiny metal reflects the heat radiation from the runner back in, this stops the runner getting cold.
REFLECTION AND ABSORBTION
Two containers were filled with warm water. They were placed in direct sunlight.
Shiny metal Dull black
because its surface absorbs heat _______ the best (sun’s energy).
__________ heat radiation. shiny metal dull black radiation shiny metal absorbing
✓ If a substance easily allows heat to move through it, we
can say it is a good conductor of heat. (metals)
✓ If a substance does not allow heat to pass through it easily
we can say it is an Insulator. (wood, plastic, glass)
✓ Why do many sauce pans have plastic handles?
Conductors
▶ Gold ▶ Water ▶ Metal ▶ Copper ▶ Aluminum
➢ Wood ➢ Styrofoam ➢ Glass ➢ Porcelain ➢ Plastic ➢ Rubber
Insulators
▶ Platinum ▶ Silver ▶ People and
Animals
▶ Trees
WHY DOES METAL FEEL COLDER THAN WOOD, IF THEY ARE BOTH AT THE SAME TEMPERATURE? ▪ Metal is a conductor…..it conducts heat away from your hands. ▪ Wood is an insulator…it doesn’t conduct the heat away from your hands as well as the metal, so the wood feels warmer than the metal.
Wood? Gold? Plastic? Glass? Water? Trees? Rubber?
insulator insulator insulator insulator conductor conductor conductor
ENERGY SOURCES AND ALTERNATIVE ENERGY