See Kit Foong

Projectile motion on an inclined misty surface: I. Capturing and analysing the trajectory

Projectile motion is usually the first non-uniform two-dimensional motion that students will encounter in a pre-university physics course. In this article, we introduce a novel technique for capturing the trajectory of projectile motion on an inclined Perspex plane. This is achieved by coating the Perspex with a thin layer of fine water droplets that allows the projectile to leave a trail as it passes. The experiment was field-tested in Singapore and the response was very good.

A datalogger demonstration of electromagnetic induction with a falling, oscillating and swinging magnet

We investigate the electromagnetic induction phenomenon for a falling, oscillating and swinging magnet and a coil, with the help of a datalogger. For each situation, we discuss the salient aspects of the phenomenon, with the aid of diagrams, and relate the motion of the magnet to its mathematical and graphical representations. Using various representation modes to guide student thinking on how the variation of the magnetic flux can be used to predict the induced electromotive force should help students develop a deeper and more coherent conceptual understanding of the phenomenon.

Can you tell the density of the watermelon from this photograph

Based on a photograph, the density of a watermelon floating in a pail of water is estimated with different levels of simplification—with and without consideration of refraction and three-dimensional effects. The watermelon was approximated as a sphere. The results of the theoretical estimations were verified experimentally.