energy. energy: where does most of our energy come from?
TRANSCRIPT
ENERGY
ENERGY: Where does most of
our energy come from?
The Sun - a giant nuclear reactor.All life depends on the sun, because plants use the
sun's energy to grow, and we can't live without plants.
What are some sources of
stored energy?
Stored Energy:Coal Oil Gasoline WoodFoodBatteries
Coal, oil and gasoline are fossil fuels. How did they form?
ENERGY
Millions of years ago, Chemical Energy is being made using sun energy: carbon dioxide + water is changed to stored energy in plants.
Plants and animals (made of carbon) are buried over millions of years, changing to oil and gas.
Where does the energy come from for plants to make food?
Chemical energy comes from these stored fuels. This is also called potential energy.
Another source of potential energy...water high up, ready to drop....
Why do these rocks have potential energy?
If they fall, what kind of energy would it be?
Kinetic energy - the energy of motion
Examples of potential energy changing to kinetic energy
What are some other forms of energy?
We have already talked about 1. potential energy 2. kinetic energy
3. chemical energy: stored energy of coal, oil,
natural gas, batteries and food.
ELECTRICAL ENERGY
SOUND ENERGY Vibrations can travel through solids, liquids and gasses.
Heat Energy
Nuclear energy- made from splitting atoms
Energy Changes
How can energy change from one form to another?Identify the forms of energy below and how it can be changed:
Energy Changes
Chemical energy from the apple is changed into kinetic energy (motion), sound energy from movement, and heat energy.
The potential energy of the water stored up high is changed to kinetic energy as it drops through the dam, which is converted to electrical energy to light the bulb, The light bulb gives off light & heat energy.
Gasoline is stored chemical energy.In the car, gas is changed to kinetic energy (motion),light energy, electrical energy, heat energy and sound energy.
The batteries have stored chemical energy.This chemical energy is changed to electrical, sound,
light and heat energy by the computer.
Light energy from the sun is changed to chemical energy in the plant.
The wood is stored chemical energy. This is changed into heat, light and sound energy as it burns.
Bonus: What kind of energy was needed to make the chemical energy stored in the wood?
Answer: the chemical energy inside the wood
came from the light energy from the sun (when it was
alive).
All life depends on the sun's energy!
Light energy is changed to chemical energy in the needles or leaves ------------>>>>>>>
Plants use water, carbon dioxide and sunlight to make sugars in their leaves, which is food for the plant to live and grow, and food for consumers like us!