Catapulting into
Project Based Learning
Applications to High School Physics
Sarah Palaich
TeachNow August 2015 Cohort

PBL in Physics
• Physics is inherently problem based, and project based
• Having projects students can work on in groups will
dramatically help increase comprehension levels.
• Projects -> discussion -> comprehension
• The catapult project discussed here includes:
collaborative design, video capture and creation, peer to
peer physics explanations, design competition, and
self/peer review and reflection.

Step 1: Design
1. Students will be split into groups randomly (I strongly
believe in making students work with peers who aren’t
their best friends).
2. The first task is to design the catapult from resources
available in the classroom. Resources can include
rubber bands, plastic spoons, popsicle sticks, but any
other materials available in the classroom can be used.
3. The pennies being catapulted must clear a one foot
barrier.

Step 2: Test and Refine
1. Students have the chance to test their catapults during
class time, preferably outdoors. They can come up with
design improvements or redesign their catapults during
this time.
2. Students learn that
failure is part of the
process and gain a better
understanding of the
physics at work.

Step 3: Record Video
1. Students decide how to record their catapult in motion
from a still frame of reference (no hand held video)
using their mobile devices.
2. They know that they’ll be asked to analyze the video,
so it’s up to them to come up with the optimal placement
of their mobile devices for this purpose.

Step 4: Analyze Video
Students analyze the motion of the penny in the videos
they’ve taken using freeze frames where they measure
using rulers/Photoshop the distance of the penny from
the ground and the catapult.

Step 5: Expand Video
1. Students decide how they want to explain the
equations of horizontal and vertical motion, which
make up projectile motion, in their video. They can
annotate their recordings of their catapult or add new
sections of video.
2. Students are tasked with being able to create clear and
concise explanations that demonstrate their own
comprehension of the materials. They are given a
rubric that both their peers and the teacher will use to
evaluate their videos.

Step 6: Critique Videos
Each group is given two
videos to critique. Students
will use a predetermined
rubric for evaluation and will
create a small video for each
group they evaluate
explaining what they thought.
Rubrics and video
responses will be returned to
the teacher and then the
original group that created
the video being evaluated.

Step 7: Competition!
Students compete against the other groups to see which
catapult has the longest range (x-distance travelled). The
prize for winning might be something like 5 bonus points
toward their final grade on the activity.
Image from: http://lhs.loswego.k12.or.us/z-alts/Conceptual%20Physics/Pictures/Pictures
%2007-08/Catapults/2nd%20Period%20Catapults.JPG

Step 8: Reflection
Students will individually write up an evaluation of the project
which includes:
A. Summary of the physics of projectile motion
B. Evaluation of the group work (shared responsibility?)
C. Evaluation of individual performance in the group
D. Evaluation of their catapult including possible
improvements.
E. Suggestions for making the activity better
F. Areas they would have appreciated more guidance

In summary
1. Students create a catapult, record the catapult in action,
annotate their video, share with and critique their peers and
reflect on the activity.
2. The materials used to build the catapults can be anything
from popsicle sticks to more advanced materials. This can
be adjusted based on school resources and age of students.
3. This activity is designed for high school physics and would
work well in either a regular physics class or an AP Physics
class since the subject matter is covered in both. The depth
of the analysis would clearly vary depending on which level
did the activity.

The result
Students gain skills:
A. Working with their peers and problem-solving
B. Understand how physics works in the real world
C. Learn that design includes failure before success
D. Learn the physics concepts well enough to teach their
peers
E. Have fun while learning physics, leading to a deeper
appreciation of science or at least not a hatred of it