Round Convex Glass Mirror, 75mm Diameter, 300mm Focal Length Mechanics_Work & Energy used to demonstrate charging by

used to demonstrate charging by induction and repeated transfer of charge

where current through a coil closes a separate contact and shows how a small signal controls a larger circuit

and polished — letting an infrared sensor compare emissivity at boiling-water temperature

fastened to a 10cm rod for clamping into retort stands during simple-machines experiments

opening to 3

Round Convex Glass Mirror, 75mm Diameter, 300mm Focal Length Mechanics_Work & Energy used to demonstrate charging byLong focal 75mm convex glass mirror at 300mm focal length and ~1. 2mm thickness, the gentlest divergence in the 75mm convex line for the largest virtual reduced images.