What is energy?
Energy is the ability to do work. We use energy for everything we do.
- A car is doing work and using energy when you go for a ride.
- A light bulb is doing work and using energy when it makes light.
- Your phone is doing work and using energy when you talk to friends.
- Trucks are doing work and using energy when they carry things from one place to another.
There are many different forms of energy.
- Motion or Kinetic Energy is what makes things move, like when you go for a run, or when an airplane flies in the sky.
- Light or Radiant Energy comes from the sun or a lightbulb.
- Heat or Thermal Energy makes things warm.
- Electrical Energy is the electricity we use in our home to keep the lights on, to make the TV work, and to keep food cold in the fridge.
- Chemical Energy is the energy stored in coal, gasoline, or other fuels that we burn to generate electricity or make a car run.
- Gravitational Energy is what holds us to the earth, and makes the earth and other planets rotate around the sun.
- Nuclear Energy is what holds atoms together.
How do we make energy?
We don’t really make energy. We convert one form of energy into another.
- A dam on a river converts the Motion Energy of the flowing water into Electrical Energy.
- When people put solar panels on their houses they are changing the Light Energy from the sun into Electrical Energy.
- When we turn on a light we are changing Electrical Energy into Light Energy.
The sun is the main source of energy on earth.
The sun’s energy comes to the earth in the form of light. Sunlight makes life on earth possible. The sun is responsible for earth’s weather, the wind, the rain, the seasons, the currents in the oceans.
Plants use the energy of the sun for photosynthesis, to create food for themselves and to grow. Animals depend on the plants for food.
SOMETHING TO THINK ABOUT
How are you using the sun’s energy when you roast marshmallows over a fire?
The energy of the fire is heat and light. When we burn wood, we are releasing little bundles of the sun’s energy that fell on earth long ago. That energy made the tree grow and it is stored in the wood.
SOMETHING ELSE TO THINK ABOUT
How many different forms of energy does it take for you to spin a fidget?
First, the energy on the sun is generated by Nuclear Energy. Then, the sun’s energy travels to earth as light. Next, plants use the Light Energy to make food, which becomes Chemical Energy. Finally, we eat the food, and we change the Chemical Energy into Kinetic Energy – movement.
That’s when we spin the fidget!
What are fossil fuels?
Fossil fuels are the remains of plants and animals that lived hundreds of millions of years ago, in the time of dinosaurs and earlier. The plants and animals that lived so long ago have been buried deep underground for all of that time, and the heat and the pressure of the earth have changed them into oil, coal or natural gas.
We burn fossil fuels to change their Chemical Energy into other forms of energy we can use, like electricity, to power airplanes, boats, cars and trucks.
What is renewable energy?
Renewable energy, also called clean energy or green energy, is energy created by nature that does not get used up.
The sun, the wind and a flowing river are examples of renewable energy.
