Balancing Pencil STEM Challenge
Objective: Balance a pencil vertically
on a craft stick
Materials:
#2 pencils
Clothespins
Pipe cleaners
Craft sticks
Tape
Procedure:
1. Tape your craft stick so that it’s half on a flat surface and half off.
2. Challenge the students to balance a pencil on the stick.
3. Challenge them to do it with a sharpened pencil and with an
unsharpened pencil.
4. After trying for a while, let the students experiment with the
clothespins and pipe cleaners. Each student will need 2
clothespins and 1 pipe cleaner.
5. Attach the center of the pipe cleaner around the pencil and
attach a clothespin to each loose end of the pipe cleaner. The
balanced weight will hold the pencil up, both sharpened and
unsharpened.
© JenniferFindley.com
Balancing Pencil STEM Challenge
Name: __________________________________________ Date: ____________________
1. Describe what happened when you tried to balance the
pencils without the assistance of the pipe cleaner and
clothespins.
2. What impact did the pipe cleaner and clothespins have
on the ability to balance the pencil? Explain how that
impact was possible.
3. What other materials could we use that would have a
similar impact? Explain.
© JenniferFindley.com
Pencil Tower STEM Challenge
Objective: Build a tower using only pencils
Materials:
#2 pencils
Procedure:
1. Create a set of rules that the
students must follow, such as:
Limit the number of pencils
Don’t allow any binding
agents
Tower must be XX high
© JenniferFindley.com
Pencil Tower STEM Challenge
Name: __________________________________________ Date: ____________________
1. What rules do I need to remember to follow while I
am constructing my pencil tower?
2. Sketch or write a plan for how you will build your
pencil tower. Label or list the materials you plan to
use.
© JenniferFindley.com
Pencil Tower STEM Challenge
Name: __________________________________________ Date: ____________________
1. Using a ruler, determine the measure of your tower.
2. What one tool, supply, or material had the biggest
impact on your tower construction? Explain.
3. If you could have used any tool, supply, or material
to help you make your pencil tower taller, what
would you use? Explain the reason for your choice.
© JenniferFindley.com
Light Refraction
Pencil Science
Objective: “Break” a pencil using water
Materials:
#2 pencils
Water
Clear Jar
Procedure:
1. Fill a jar halfway with water.
2. Ask the students, “Can you break a pencil without touching it?”
3. Let the students experiment with trying to break their pencils
using the jar, water, and pencils. Some of the students might find
the answer without help, but others won’t.
4. If the students can’t figure it out, show them how to place the
pencil in the water and tilt the pencil and jar so that the pencil
appears broken when you look at it from the side.
5. Explain that the pencil looks broken due to light refraction. Light
refraction happens when something causes the light waves to
bend. Usethe reading text on the next page to help explain the
concept.
© JenniferFindley.com
Light Refraction
Pencil Science
You might have heard the phrase “the speed of light.” You might have even
learned that the speed of light is constant. Constant means it’s never changing.
However, the speed of light is only constant in a vacuum. A vacuum means empty
space where there are no other materials present- not even air! In a vacuum, light
travels at a constant speed and in a straight line.
The speed of light is not constant, though, when it passes through transparent
materials such as air, water, or glass. These are called mediums. It’s not just speed
that’s affected. Direction is affected, too. Light passing through a medium no longer
travels in a straight line. The result of a medium’s influence on light is called
refraction.
Different mediums have different qualities. They make light bend or turn in
different ways. Consider jumping through the air. Now, consider jumping while
standing shoulder-deep in a lake. The second medium – water – has a greater
impact on speed and motion than the first – air. The same goes for the motion and
speed of a ray of light.
This is why a pencil sticking out of a glass of water will appear broken. You’re
seeing the pencil through two different mediums. The part sticking out of the glass is
seen through air. The part submerged is seen through a combined medium of glass
and water. Each medium has a separate influence on the way we perceive the
pencil. Each changes the direction and speed of light in a different way. Scientists
have used these same principles of refraction to make lenses for eyeglasses,
microscopes, and telescopes. They’ve learned to shape mediums like glass in a
precise way that enables them to use refraction as a helpful tool.
1. Using the information in the text, explain how the pencil
placed in the water appeared broken.
2. How does knowing about refraction benefit the world of science?
© JenniferFindley.com
Light Refraction
Pencil Science ANSWERS
You might have heard the phrase “the speed of light.” You might have even
learned that the speed of light is constant. Constant means it’s never changing.
However, the speed of light is only constant in a vacuum. A vacuum means empty
space where there are no other materials present- not even air! In a vacuum, light
travels at a constant speed and in a straight line.
The speed of light is not constant, though, when it passes through transparent
materials such as air, water, or glass. These are called mediums. It’s not just speed
that’s affected. Direction is affected, too. Light passing through a medium no longer
travels in a straight line. The result of a medium’s influence on light is called
refraction.
Different mediums have different qualities. They make light bend or turn in
different ways. Consider jumping through the air. Now, consider jumping while
standing shoulder-deep in a lake. The second medium – water – has a greater
impact on speed and motion than the first – air. The same goes for the motion and
speed of a ray of light.
This is why a pencil sticking out of a glass of water will appear broken. You’re
seeing the pencil through two different mediums. The part sticking out of the glass is
seen through air. The part submerged is seen through a combined medium of glass
and water. Each medium has a separate influence on the way we perceive the
pencil. Each changes the direction and speed of light in a different way. Scientists
have used these same principles of refraction to make lenses for eyeglasses,
microscopes, and telescopes. They’ve learned to shape mediums like glass in a
precise way that enables them to use refraction as a helpful tool.
1. Using the information in the text, explain how the pencil
placed in the water appeared broken.
The pencil appeared broken because the pencil was being seen through two
different mediums. The part not in the water was seen through air. The part in the
water was seen through both glass and water, making it look different.
2. How does knowing about refraction benefit the world of science?
Understanding the concept of refraction benefits science because it has allowed scientists
to use that knowledge to make lenses for eyeglass, microscopes, and telescopes.
© JenniferFindley.com
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Jennifer Findley
