Junior Paddleboat

 As the virus numbers climbed and the weather got cold, I moved to Zoom meetings and I decided to try mechanical engineering.  The Juniors made paddleboats.  

Requirements

According to Badge Explorer, the requirements were:

Explore how paddle boats work and engineer your own paddle boat.

• Explore how paddle boats work
• Design and build a rubber band-powered paddle boat 
• Test your rubber band-powered paddle boat 
• Analyze and share your results 
• Brainstorm ways to improve your design

When you've earned this badge, you'll know how to build and test a paddle boat and understand buoyancy, potential energy, and kinetic energy.

Sources

I used the plans in VTK, along with the plans from Girl Scouts of Southeast Florida. 

Our Meeting

I had asked girls to find some things they thought would float and some things they did not think would float.  I had also asked parents to have a buckect/pan/sink of water available.  We tested things and talked about why some floated and some didn't---and why some floated for a while but eventually sunk.  

The initial hypothesis was that light things floated and heavy things sunk.  I then asked if it was easy to pick up a coin and of course they said yes.  I asked if they had ever seen boats or ships on the river or lake, and they said yes.  I asked if they could pick up the boats/ships and of course they said no and then I talked about weight vs size and how that held stuff up--made it buoyant.  

Next we reviewed potential and kinetic energy and how we could store energy in various ways, like twisting a rubber band or lifting things up high.  

The parents had picked up packets with rubber bands and pencils and I showed the video on the plan from GSSF.  The girls then made the boats, tested them and adjusted them.  

We had trouble getting the boars to move.  I think the rubber band for the propeller should have been smaller.  We did find that moving the pencils down further on the container helped.  Still getting the wheel situated so that it spun and hit the water was hard--and the power source did not last long