Science can be fun for a couple of boys who have a fascination with shooting things. Even homemade triangular catapults can entertain for quite some time.
There is nothing more satisfying than shooting a wildly inaccurate device and without warning or anticipation hearing the hollow thud that a large flying marshmallow makes when it hits your opponent solidly on the forehead.
Actually, the sound is not so much a “thud” as a “PFLATT.” It is entirely delightful to hear!
Knowing Your ABCDs 