Float Your Boat Challenge
An object will float if the gravitational (downward) force is less than the buoyancy (upward) force. So, in other words, an object will float if it weighs less than the amount of water it displaces. This explains why a rock will sink while a huge boat will float. The rock is heavy, but it displaces only a little water.
Task
Your task is to design and build a boat to ferry an unopened can of beans down a length of water. A bathtub or paddling pool would be great! What could be easier… dive into your recycling and get creative, get wet and have some fun!
Resources
- Recycling supplies or whatever you have lying around.
- Duct tape
- Sellotape
- Baking paper
- PVA glue would also be very useful but you can do it without.
Instructions
- Design your boat – What do you fancy? A raft, a galleon, a punt, a canoe, a junk, a liner, a paddle steamer… Boats can be pretty much any shape or size so whatever design you choose remember it needs to be stable enough to float and buoyant enough to carry a can of beans (or similar). How you power your craft is up to you. It can be a boat you push, it can have sails which you can fan, you can even power it by paddles and elastic bands.
- Build your boat – You can build your boat out of waterproof material (like plastic) or you can build it out of more adaptable material (like cardboard) and waterproof it.
- Test your boat – You can check out your boat in a bowl of water – make sure it floats empty before you add any weights to it. Choose small weights to start with and check the water line before
adding extra weight. - Decorate your boat – When you are sure you have a working model you can decorate your boat – but don’t add too much weight.
- Video your boat – Pop your boat into your bathtub (or paddling pool) and film it on its journey.