We have been studding the basics of physics in class. To better understand the physics that we have
been working with we are going to build a catapult. By the due time of this project we will have also
discussed simple machines and complex machines. All of this will be combined to create our catapults.
This project will not only consist of building a catapult but there will also be a research paper that is
involved with the creation of the catapults.
The due date has not been fully determined but it will be towards the end of the 4th 9weeks. I am giving
this out early so that the students have ample time to complete the activity.
There are three basic designs of catapult that can be built for this project. These three are the traditional
torsion type, the ballista type, and the trebuchet type.
This type of catapult uses the energy stored in a rope bundle to rotate
an arm. This was the type of catapult that the Greeks first used and
the Romans later perfected.
This type of catapult was first used by the Romans. It is basically two
torsion catapults turned on their sides and the arms joined to create a
giant crossbow. If you decide to build this style catapult you need to
remember that is has to be able to fire a ping pong ball.
This type of catapult was developed in Europe and perfected by the
French during the Middle Ages. This type uses a counter weight to
sling an object.
The goal of this project is to build a small scale catapult that is able to throw a ping pong ball and
accurately hit a target at 20ft.
1. Catapult must be able to fit into a box that is 45cm x 30cm and no taller than 90cm.
2. The catapult must be one of the three basic types, modified designs are allowed.
3. The ammo that will be fired will be a ping pong ball sized projectile.
4. Any type of materials may be used in making the catapult, as long as they comply with the School
Boards rules and regulations.
A research paper is required for this project. The paper must be at least 3 pages in length, typed double
spaced. It must also have with it a cover page with title, name, hour, and date. A bibliography is also
needed for the paper. The must detail the history of your chosen catapult design, as well as why you
choose that style. A materials list and a rational of the materials used will also be required
The Grading system:
10 15 20 25
Basic design / Basic design /
Catapult Well made / modifications
Minimal effort Moderate effort put Good effort put
(Type/Creativity) make to basic design
into it. into it
Catapult Works but does not Works and throws Ping Pong
Does not work throws Ping
(Functionality) throw Ping Pong Ball Ball at least 20ft
Some history Full history ( the use and
Minimal history (where it was first Most History creation of the type of
All of the
Paper All of the preceding All of the preceding plus
What type of preceding plus
(Rational of plus why you why you used those
catapult what makes the
Catapult) choose this design materials
There will be a 36” target placed at 20ft from the firing line. The students will fire 3 ping pong balls at
the target. The total points earned by hitting the target will be added to the final grade as bonus points.