These flying cups are a great STEM challenge for any time of year. One cup acts as an elastic band launcher, and the other is launched into the air! It's a fun way to learn about forces, motion, elasticity and gravity!
When the cup to be launched pushes down on the elastic bands, they become stretched, storing elastic potential energy. When the cup is released, the potential energy in the elastic bands is converted into kinetic energy, which is then transferred to the flying cup, launching it into the air.
Flying Bat and Pumpkin STEM Challenge
Materials
- 3 paper cups
- 2 elastic bands
- Sellotape
- Pencil
- Card and paper to decorate - optional
Instructions
Using a sharp pencil, carefully poke four holes in the cup as shown below. Ask an adult to help.
Cut the elastic bands into a single, long strip.
Thread the elastic bands through the holes in the cup as shown and secure the ends with tape. This is the mechanism that will catapult the paper cup bats into the air. Put this cup inside another cup (this is just so it looks better and is not necessary).
Decorate a second paper cup to look like a bat or other Halloween theme.
Push a decorated cup into a cup with elastic bands and let go.
It should shoot up into the air.
What's going on?
When the elastic bands in the launcher cup are stretched, energy is stored in the bands. We call this elastic potential energy. The more the elastic band is stretched, the more potential energy it has.
The elastic potential energy stored in the stretched bands is first converted into kinetic energy as the bands contract. This kinetic energy is then transferred to the paper cup, launching it into the air.
Take care not to stretch the elastic bands too much, as if they are stretched beyond their elastic limit, they become damaged and won't spring back.
If you enjoyed this activity, don't forget to give my other Halloween STEM challenges a try.
Last Updated on October 23, 2025 by Emma Vanstone
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