Can you make Rudolph fly? It’s actually more about making him fall and then fly. This STEM Project is a great lesson on buoyancy that goes slightly past the sink or float type tests!
Can you make Rudolph Fly?
Ketchup packet (others work too, just test them out)
Small reindeer drawing on paper
Bottle (larger is better, 1lt or more)
Hot Glue Gun and Glue
Start by filling up your bottle with water. Feel free to decorate if you wish! Our Rudolph definitely wanted to fly through the clouds.
Next, make your reindeer. Draw or print out a small reindeer. Cut it out, laminate, and then cut around it again. Make sure to cut twice. If you cut the image and the lamination at the same time, there will be a layer of paper exposed to the water. Then your reindeer will be waterlogged!
Use a glue gun to glue your reindeer to your ketchup packet. Then let it set.
Tell your reindeer to enjoy his trip and wave goodbye! Or just push him into the bottle without getting sentimental.
The ketchup packet should float at this point. (If not, I’ve included some troubleshooting tips at the bottom).
I highly recommend testing your bottle, water, and ketchup pack before doing this with a kid! Some packets just don’t work.
Squeeze the bottle until your reindeer sinks to the bottom. Release to let him fly again. Continue this process to let him rise and fall as much as you please!
He should be able to sink all the way to the bottom!
Why does it work?
In short – buoyancy! Buoyancy refers whether objects sink or float. Something will float in water if it is less dense than the water.
So we can say the ketchup pack is less dense than water because it floats.
However, it also sinks. Why?
Ketchup packs have a little pocket of air in them. When the bottle is squeezed, the air pocket is condensed. This causes the ketchup packet to become denser than the water and it sinks.
Here is a great video on buoyancy for kids!
If your ketchup packet sinks at the beginning – add some salt to your water. It’ll make the water denser. Careful not to add too much salt or your ketchup pack won’t sink when you squeeze the bottle.
The ketchup pack won’t sink when squeezed – try different water (bottled instead of tap) or a different ketchup packet. Also, consider trying different temperatures of water or different amounts in the bottle.
Great more great Christmas STEM Ideas here:
Galaxy Snow Globes DIY :: Figment Creative Labs
Christmas STEAM for Kids | Wreath Activity :: Preschool Powol Packets
Holiday Magic Milk :: Science Kiddo
Building a Molecular Structure with Cranberries :: From Engineer to Stay at Home Mom