01 Invent Yourself: Pinhole sunglasses
02 Disc spectrometer
03 Snail ball
04 Singing capacitor
12 Dotted line trick
01 Invent Yourself: Pinhole sunglasses
02 Disc spectrometer
03 Snail ball
04 Singing capacitor
12 Dotted line trick
Under certain conditions, when a piece of chalk is dragged across a blackboard, the resulting trace is not a continuous line but a periodic sequence of dots, even though the motion is uninterrupted. This can happen with other writing materials and surfaces. Investigate the physical parameters that govern this phenomenon.
