Various 'tricks' are possible using either a Van de Graaf or the rods/fur to demonstrate electrostatic forces.
Moving Sphere--One of the spherical capacitors is made to stand unstably. Electrostatic force causes the capacitor to wobble back and forth as it charges and discharges.
Rotating 2M stick--A two-meter stick is balanced on a lead ball. A charged rod is held near one end. Electrostatic induction causes the stick end to 'follow' the rod.
Rice crispies/styrene pellets--Styrene pellets in a flask undergo erratic motion when the flask is placed near the Van de Graaf. Rice crispies also work, flying around quite dramatically.
Deflection of Water Stream--Demonstrate the principle of electrostatic spray painting. A water stream (water gun) sprayed past the Van de Graaf will charge and then break apart in a coarse/fine mist.
Propelled Hoop-- A light aluminum ring is propelled by a charged rod placed in front of it, causing a gradient in the electric field.
See Also: Van de Graaf Generator
References Hecht, Chpt. 17, pg. 657
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