Fire a Ball the Furthest

Requirements:

The objective of this activity is to fire a small ball the furthest using the equipment provided. The equipment listed above is by no means what you have to use - it was simply what I had available.
Either split the troop into equal teams of around 5 or use the patrol system. Provide each team/patrol with exactly the same pieces of equipment and ask them to construct apparatus which will fire a small ball. The winning team/patrol is the one who fire the ball the furthest.
This activity should demonstrate the abilities/skill/qualities of each Scouts:
- Leadership
- Team building
- Being a team member
- Knots
- Lashings
- Ingenuity
- Lateral thinking
- Competitiveness
Each team's design was something like:
The main thing this activity highlighted to me was the Scouts inability to do tripod lashings!.