| Energy To
Live and Move
Think about what happens when you are
riding your bike. How are you able to pump the pedals, go over jumps, and skid to a stop?
All these actions are powered by energy. Energy is what creates movement in the
world. It allows athletes to run, trees to sway, water to drip, and planes to fly. Without
it, nothing would move, including you.
All living things need energy to function.
When you walk, talk, eat, laugh, or even sleep, you are using energy. Plants need energy
to grow and make seeds. Even tools like computers and flashlights need energy to operate.
We depend on energy to heat our homes,
cook our food, run our machines, and light our streets. As the human population grows and
engineers design more and more machines, the demand for energy around the world will keep
going up.
Forms of Energy
Where does energy come from? Almost all
energy on Earth comes from the sun. The food we eat, the gas we put in our cars, even the
electricity that lights our houses can all be traced back to energy from the sun. Without
the sun, Earth would be totally dark and freezing cold.
Light and heat are both forms of energy
that come directly from the sun. Light allows us to see during the day and gives plants
the energy they need to make food. Heat from the sun warms everything on Earth, including
our bodies. We can also create light and heat using other forms of energy.
Food is a form of energy we use to
power our own bodies. Fuel, such as coal and oil, is another form. It is usually
found deep in the ground and must be dug up with big machines. Other forms of energy
include wind and water. Strong winds blowing across a field contain energy and so does
swiftly moving river water.
Electricity is a type of energy
that people make using other kinds of energy found in nature, such as wind, oil, or coal.
Energy that comes into our homes as electricity can be used to light reading lamps, run
the vacuum cleaner, or make popcorn. Do you ever play computer or video games? The energy
needed to run these games comes from electricity.
Sarah Martin/Writing
Sample/Harcourt Brace School Publishers/Grade 3/PE
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