Sophie Duncan explains how boomerangs bring us back to some basic laws of physics.
Boomerangs come in all shapes and sizes, but everyone knows what they should do. Unfortunately it is not enough to have a boomerang, you also need to develop the skills required to throw it.
Aborigines hunted with sticks, which they threw at their prey. They developed sticks that travelled easily through the air, and could be accurately targeted. This hunting stick was the direct forerunner of the boomerang.
Although the boomerang has developed as a recreational toy, it has also found use in hunting birds. The hunter would make a call like a hawk, and throw the boomerang. The birds were fooled into thinking a hawk was nearby and took flight, getting trapped in nets set up by the hunter.
Understanding how a boomerang works requires knowledge of Newton's Laws of motion, gyroscopic stability and the Bernoulli effect. Experimenting with different designs makes it possible to explore how these physical laws affect the behaviour of the boomerang, and how to perfect your throwing technique.
The easiest boomerang to make at school consists of two straight pieces of A4 card. Cut two 10cm-wide pieces from the long edge of the card. Stick these together to form a cross. Fold each of the four ends of the cross up 2cm to form a right angle. The boomerang will lie flat on a table, with all four tips pointing upwards. Take your boomerang outside and throw it away from you vertically (not horizontally, like a Frisbee). With a bit of practice you'll get it to come back.
Sophie Duncan is a physicist and programme manager with Planet Science (formerly Science Year)www.planet-science.com