Resonance

 Seeing Simple Harmonic Motion everywhere. If we vibrate this wire too much it snaps and the piano wire did, which led to interesting discussions on metal stress and fatigue.

Milk

 It was interesting talking to students about Milk and the things I learned. Generally, milk was perceived as being unhealthy for you - way too much fat content ( 3.5%) and many of the alternatives chosen were based on advertising rather than any accurate information.

Modern Webpage Design

 The computing books look at Web pages designed using Notepad, which is what I taught 30 years ago. We looked at more modern software like Nicepage and others to create webpages that do all the clever things and how much web pages have changed through the years.

Electric Fields

Creating parallel and radial electric fields from a Static electric feed rather than an EHT device. It works better.

 

Fractional Distillation of Oil

Starting with Synthetic Crude Oil the students heated the oil progressively heating it to a higher temperature and collecting the fractions. The first fraction burnt but the subsequent ones apart from the last wouldn't burn.

 

Pressure inside a ballooon

 Is the pressure inside an inflated balloon greater than that in a deflated balloon? The debate raged on until with a @Pascoscientific wireless pressure sensor proved that the pressure was indeed 1.1 KPa higher in the inflated balloon - the elasticity of the balloon to blame.

Curves

 Now draw a nice smooth curve through all the points