Friction, turning and other effects
This collection has experiments where forces cause a variety of effects. There are instances of resistive forces - friction, solids falling through fluids such as air or liquids. Forces also cause objects to rotate. Insight into the lever principle is empowering because of its great range of applications.
Surface tension and the Bernoulli effect can be intriguing. They call out for explanation and so, at advanced level, easily lead on to discussion of relevant physical theory.