The Catapult
Objective:
To launch a tennis ball the closest possible to a target located 12 meters away from the launch area using
a catapult activated by mechanical and/or electrical means.
Background:
The catapult is an activity designed to allow students to apply the motion laws they studied in their
mechanics class. They will also have the opportunity to use their knowledge of electromagnetism and/or
mechanics to design an elegant way to activate the catapult.
The Competition:
The rules are as follow:
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The catapult must be activated using a mechanism initially started by dropping a metallic
ball (27 mm diameter) into the launch mechanism of the catapult.
The mechanism designed to activate the catapult must use principles of electromagnetism
or mechanics or both (your instructor might require you to use either one of those
depending on your current physics level). If using electromagnetism, a 12 VDC / 0.5 A
(max) electrical signal will be provided and must be utilized in the launch mechanism. No
batteries allowed.
The projectile that will be launched by the catapult is a standard tennis ball (approximately
6.7 cm diameter)
There is no weight limit on the catapult but it must be able to fit in a box measuring
1 m x 1 m x 1.5 m when in its-ready-to launch position
The target for the catapult will be located twelve (12) meters away from the launch area.
Points will be allocated according to the following:
1) Distance from the target:
 0 – 0.1 meter from the target: 0 point
 0.1 – 0.2 meter from the target: 1 point
 0.2 – 0.4 meters from the target: 2 point
 0.4 – 0.6 meters from the target: 3 points
 0.6 – 0.8 meters from the target: 4 points
 0.8 – 1.0 meters from the target: 5 points
 1 – 2 meters from the target: 7 points
 More than 2 meters from the target: 10 points
2) False starts:
- 3 points for each attempt to launch the tennis ball that is unsuccessful
The team with the least amount of points will be proclaimed winner.
Each team will have 2 trials (on the spot) and the opportunity to come back a third time after
they discuss improvements and adjustments that can be made to their design.
Materials supplied:
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Tennis ball (6.7 cm diameter)
Metallic ball (27 mm diameter)