Uses of Energy
Force, Motion, and Energy
Energy Transformations
Lexile 770L
1
Energy is everywhere. Energy can be found
naturally in the wind, on the ground, and even in
our bodies. Energy is in our motion, and it exists
in falling rain.
2
Most of the energy on Earth can be traced back
to our nearest star, the Sun. The Sun sends us
energy that we detect as light. It also sends us
energy that is not easily visible to us. For
instance, when the Sun’s energy reaches Earth,
it is used by plants to make food, it warms the
land and the oceans, and it contributes to the
water cycle.
3
Energy can do so many different things because it is constantly changing. Energy is never
created or destroyed. However, it can transform from one type of energy to another. This fact
is referred to as the law of conservation of energy. When we say that energy is conserved,
we mean that it never disappears but changes from one type of energy to another.
4
It is easy to think that energy disappears. Take sound energy, for example. If you are standing
close to a bell when it rings, it sounds quite loud. The farther away you move from the sound
the quieter it gets. When you are really far away, you might not hear the bell at all. Does that
mean that some of the sound energy disappeared? The truth is that the sound energy just
changed into heat energy. Sound energy was not lost. It just changed forms and transformed
from one kind to another.
5
Humans have figured out how to harness these energy changes, and this allows us to do
many things. Take electric light, for example. Electrical energy flows into the filament of a light
bulb where it changes from electrical energy into light energy. How does this happen? The
electrical energy makes the filament so hot that it glows and changes into heat and light
energy. Then, the light brightens a room, and heats the air and objects around it. Thus, the
light energy transforms back into heat energy.
6
Energy can even be transformed inside your body. During the process of photosynthesis,
plants use the Sun’s energy to make food. The energy from the Sun becomes chemical
energy inside an ear of corn or a leaf of spinach. When you eat the plants, the chemical
energy becomes kinetic energy. This helps your body move.
1
Uses of Energy
Force, Motion, and Energy
Continued
7
To sum it up, energy is all around you, it never disappears, but it can transform from one kind
to another.
2
Uses of Energy
Force, Motion, and Energy
1
2
The best summary of this passage would be:
A
People can use energy in many ways.
B
Energy is neither created nor destroyed, only transformed.
C
All energy comes from the Sun, our nearest star.
D
Energy transformations can happen inside your body.
Which chain of energy transfers best represents how this toaster works?
A
1) Heat 2) Light 3) Mechanical
4) Electrical
B
1) Light 2) Mechanical 3) Heat
4) Chemical
C
1) Light 2) Electrical 3) Heat
4) Mechanical
D
1) Electrical 2) Chemical
3) Mechanical 4) Heat
3
Uses of Energy
Force, Motion, and Energy
3
4
5
Which word is the best synonym for the word harness (paragraph 5)?
A
Use
B
Share
C
Change
D
Destroy
Another good title for this passage would be:
A
The Sun
B
Electrical Energy
C
The Law of Conservation of Energy
D
Useful Energy
The author organized this passage by:
A
Comparing and contrasting the different types of energy
B
Describing a problem and explaining how to solve it
C
Sequencing the changes that energy goes through
D
Illustrating the law of conservation of energy with examples
4