Structures Around
the World
Student Journal
After School STEM Academy
6-8th Grade
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ACTIVITY 1: PAPER BRIDGES
Summary
Can you build a bridge that holds up to 100 pennies, using only 1 sheet of paper and up to 5
paper clips?
Objectives
! Use paper to build a bridge between
two stacks or books or desks.
! Design & redesign bridge to hold
maximum amount of weight
(pennies).
Materials
5 pieces of paper (per group)
paper clips
pennies
yardstick (share between groups)
Activity
1. Present the criteria and constraints for this building challenge:
a. Your group of 3-4 students must construct a bridge that spans two desks or two
stacks of books (at least 8 inches).
b. You may use one piece of paper and up to 5 paper clips.
c. Your bridge must have enough room underneath it to allow a rubber duck to
pass underneath (to represent a boat).
2. In your group, discuss possible ideas before you start building. Sketch your ideas on the
next page. What can you do to the paper to make it stronger?
3. When you have decided on an initial design, construct your bridge.
4. Place the bridge across two supports (desks or books) that are 8 inches apart.
Remember that the space below the bridge must be clear to allow boats (rubber duck)
to pass!
5. To test your bridge, load it with pennies one at a time, until it collapses. Record your
results.
6. Redesign your bridge to try to hold more pennies – be creative in how the paper is
folded and how paper clips are used.
Adapted from: http://www.pbs.org/wgbh/buildingbig/educator/act_paper_ei.html
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ACTIVITY 1: PAPER BRIDGES
Bridge Design #1
What worked well?
What needs improvement?
Adapted from: http://www.pbs.org/wgbh/buildingbig/educator/act_paper_ei.html
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ACTIVITY 1: PAPER BRIDGES
Bridge Design #2
Did your re-designed bridge work better?
What still needs improvement?
Adapted from: http://www.pbs.org/wgbh/buildingbig/educator/act_paper_ei.html
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ACTIVITY 1: PAPER BRIDGES
Background: What is going on?
Bridges illustrate the effect of weight or another force at a distance from a pivot or support
point (torque), and they also provide experience with beams. In this activity, students
experiment with a variety of shapes such as folded corrugations and rolled tubes that can make
an inherently weak material such as paper much stronger. Paper is very weak under
compression and is somewhat stronger under tension (i.e., it collapses when you push the ends
together but it doesn't pull apart easily). When you put weight on a sheet of paper it tends to
buckle because it is very thin. It has no strength along the thin direction. By folding or rolling
the paper, you create a "thickness" which allows the paper to reinforce itself and not collapse
so easily.
Vocabulary
civil engineer: A person who applies her/his understanding of science and math to design projects
such as highways, buildings, bridges and all types of structures for the benefit of humanity and
our world
compressive strength: The amount of compressive stress that a material can resist before failing.
cross-sectional area: A "slice" or top-view of a shape (such as a girder or pier).
force: A push or pull on an object, such as compression or tension.
girder: The "beam" of a bridge; usually horizontal member.
load: Any of the forces that a structure is calculated to oppose, comprising any unmoving and
unvarying force (dead load), any load from wind or earthquake (environmental load), and any
other moving or temporary force (live load).
member: An individual angle, beam, plate or built piece intended to become an integral part of
an assembled frame or structure.
pier: The "column" of a bridge; usually vertical member.
tensile strength: The amount of tensile stress that a material can resist before failing.
truss: The structural frame that comprises a set of triangles made of straight members and
joints. A truss is typically made of steel or wood. Structural trusses distribute tension and
compression forces along the bridge.
(adapted from https://www.teachengineering.org/lessons/view/cub_brid_lesson02)
Adapted from: http://www.pbs.org/wgbh/buildingbig/educator/act_paper_ei.html
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ACTIVITY 2: CLAY BRIDGES
Summary
Last week you used paper to create a bridge that can hold weight. This week, you will use clay
to experiment with bridge design to make the longest bridge possible.
Objectives
! Use clay to build a bridge between
two stacks of books or desks.
! Explore the forces of tension given a
stretchy material.
Materials
8oz of clay (per group of 3-4 students)
yardstick (share between groups)
Activity
1. Present the criteria and constraints for this building challenge:
a. Your group of 3-4 students must construct a bridge that spans two desks or two
stacks of books (at least 6 inches).
b. You may use 8 oz of clay.
c. The bridge must support its own weight and may not be anchored using any
other material.
d. You must try to make your bridge as long as possible.
2. In your group, discuss possible ideas before you start building. Sketch your ideas on the
next page. How will you manipulate the clay to make it stronger? When you have
decided on an initial design, construct your bridge.
3. Build your bridge. Redesign it to make it as long as possible. Be sure to sketch your
designs, and note how long of a bridge you are able to create.
Background: What is going on?
In building bridges, students can observe the effects of the weight of structure itself, as well as
the effects of other forces acting on the structure. As the structure is lengthened, anchoring the
ends (without using anything other than clay) can become a problem; students can observe
tension and compression where the clay meets the edges of the tables.
Adapted from: https://www.exploratorium.edu/structures/claybridges.html
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ACTIVITY 2: CLAY BRIDGES
Design #1:
How long is your bridge?
How could you make it longer?
Adapted from: https://www.exploratorium.edu/structures/claybridges.html
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ACTIVITY 2: CLAY BRIDGES
Design #2:
How long is this bridge?
Did your improved design make it longer? Why?
Adapted from: https://www.exploratorium.edu/structures/claybridges.html
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ACTIVITY 3: NEWSPAPER BRIDGES
Summary
This week, you will use newspaper and tape to build a bridge that spans at least 18 inches and
supports the weight of at least one book.
Objectives
! Use newspaper to build a bridge
that can support the weight of at
least one book.
! Explore more complex structural
design to create a strong bridge.
Materials
Newspaper
Tape
Books (not included in kit)
Yardstick (share between groups)
Activity
1. Present the criteria and constraints for this building challenge:
a. Your group of 3-4 students must construct a bridge that spans two desks at least
18 inches apart.
b. You may only use newspaper and tape.
c. The bridge must support its own weight and may not be anchored using any
other material.
d. The bridge must support the weight of at least one book.
2. In your group, discuss possible ideas before you start building. Sketch your ideas on the
next page. How will you manipulate the clay to make it stronger?
3. Build your bridge. How well does it work?
4. Redesign it to meet the criteria and constraints. Be sure to sketch your designs, and
note how many books your bridge is able to support.
Background: What is going on?
Building bridges demonstrates the effect of weight or another force at a distance from a pivot
or a support point (torque). In addition, it makes clear the need for the upward support of the
bridge to counteract the downward force of the load. One of the clearest principles illustrated
in this activity has to do with beams. If the span of the newspaper bridge is considered as a
beam, the crushing and bending of the bridge under its load make the stresses on the beam
quite evident.
Adapted from: https://www.exploratorium.edu/structures/newspaper.html
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ACTIVITY 3: NEWSPAPER BRIDGES
Design #1:
Where does the bridge start to break? What do you think is happening?
How many books did it support?
Adapted from: https://www.exploratorium.edu/structures/newspaper.html
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ACTIVITY 3: NEWSPAPER BRIDGES
Design #2:
Were you able to make improvements to your design? How?
How many books did it support?
Did you get stuck or run into any problems? How did you overcome them?
Adapted from: https://www.exploratorium.edu/structures/newspaper.html
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ACTIVITY 4: PAPER TABLE
Summary
This week, you will use newspaper and tape to build a table that is strong enough to hold the
weight of at least one book.
Objectives
! Use newspaper to build a table that
can support the weight of at least
one book.
! Explore structural design of a table.
Materials
Newspaper
Cardboard (8.5x11”)
Tape
Books (not included in kit)
Yardstick (share between groups)
Activity
1. The challenge is to design and build a table out of newspaper tubes. Make it at least
eight inches tall and strong enough to hold a heavy book.
2. Present the criteria and constraints for this building challenge:
a. Your group of 3-4 students must construct a table that is at least 8 inches tall.
b. You may only use newspaper, 1 piece of cardboard, and tape.
c. The table must support its own weight.
d. The table must support the weight of at least one book.
3. In your group, discuss possible ideas before you start building. Sketch your ideas.
a. How can you make a strong tube out of a piece of newspaper?
b. How can you arrange the tubes to make a strong, stable table?
c. How can you support the table legs to keep them from tilting or twisting?
d. How level and big does the table's top need to be to support a heavy book?
Adapted from: http://pbskids.org/designsquad/parentseducators/resources/paper_table.html
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ACTIVITY 4: PAPER TABLE
4. Use the materials to build your table. Then test it by carefully setting a heavy book on
it. When you test, the design may not work as planned. If things don't work out, it's an
opportunity—not a mistake! When engineers solve a problem, they try different ideas,
learn from mistakes, and try again. Study the problems and then redesign.
Paper Table Design:
How many books did your paper table hold?
Adapted from: http://pbskids.org/designsquad/parentseducators/resources/paper_table.html
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ACTIVITY 4: PAPER TABLE
Troubleshooting:
• the tubes start to unroll—Re-roll them so they are tighter. A tube shape lets the load (i.e., the
book) push on every part of the paper, not just one section of it. Whether they're building
tables, buildings, or bridges, load distribution is a feature engineers think carefully about.
•
the legs tilt or twist—Find a way to stabilize and support them. Also check if the table is
lopsided, too high, or has legs that are damaged or not well braced.
•
a tube buckles when you add weight—Support or reinforce the weak area, use a wider or
thicker-walled tube, or replace the tube if it's badly damaged. Changing the shape of a material
affects its strength. Shapes that spread a load well are strong. Dents, creases, and wrinkles that
put stress on some areas more than others make a material weaker.
•
the table collapses—Make its base as sturdy as possible. Also, a table with a lot of triangular
supports tends to be quite strong. A truss is a large, strong support beam. It is built from short
boards or metal rods that are arranged as a series of triangles. Engineers often use trusses in
bridges, buildings, and towers.
Discussion
1. How many books did your most successful design hold?
2. What did you notice about successful paper tables? What make them strong?
Adapted from: http://pbskids.org/designsquad/parentseducators/resources/paper_table.html
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ACTIVITY 5: ZIP LINE
Summary
The previous weeks challenges have focused on structural design. For your final challenge of
this session, you will design and build something to carry a Ping-Pong ball from the top of a zip
line to the bottom in four seconds or less.
Objectives
! Explore how to
keep something
balanced.
! Identify ways to
reduce friction.
Materials
Per 3-4 students:
Chipboard
Small paper cups (4)
Ping-Pong ball
Plastic straws (4)
Scissors
Wooden skewers (4)
Tape
Washers (4)
For the whole class:
Hole Punch
Fishing line (4 ft)
Activity
1. Look at your materials and think about the questions below. Then sketch
your ideas below. Your group of 3-4 students must build something to
carry a Ping-Pong ball from the top of a zip line to the bottom in four
seconds or less.
a. Using these materials, what can you design that can carry a PingPong ball down a zip line?
Adapted from: http://pbskids.org/designsquad/parentseducators/resources/zip_line.html
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ACTIVITY 5: ZIP LINE
b. How will your Ping-Pong ball carrier stay on the zip line as it goes from the top
to the bottom?
c. What kinds of materials should be in contact with the zip line so that the carrier
slides quickly?
2. Test the carriers by putting them on the line.
3. If your Ping-Pong ball carrier:
a. keeps dropping the ball—Check that it has a big enough place to hold the ball.
b. stops partway down—Make sure there’s nothing blocking your carrier where it
touches the line.
c. doesn’t balance well—Adjust the weights. Add weights or move them so they are
farther below the zip line. Doing this changes the carrier’s center of gravity, the
point within an object where all parts are in balance with one another. See how
changing the numbers and positions of washers affects the carrier’s balance.
d. takes longer than four seconds to travel the zip line—Find ways to reduce friction.
Yes, there’s friction—the force that resists motion—even when you’re dealing
with something as smooth as fishing line. You’ll find friction anytime things rub
together. Experiment with different materials to see if you can reduce friction
and speed up the Ping-Pong ball carrier.
Reflection
What was your favorite activity this session? Why?
What would you like to design next?
Adapted from: http://pbskids.org/designsquad/parentseducators/resources/zip_line.html
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