Wooden Friction Block Set with Plain, Felt, and Sandpaper Surfaces Capacity_150mL comparing thermal-radiation emissivity from surfaces

comparing thermal-radiation emissivity from surfaces at identical temperature

and narrow — at 10 inches tall

Used to compare EMFs and measure internal resistance by the null-deflection method

Built for introductory electricity instruction

Greatly magnified transverse monocot stem section on a mounted base exposes scattered vascular bundle layout for advanced plant anatomy coursework

Wooden Friction Block Set with Plain, Felt, and Sandpaper Surfaces Capacity_150mL comparing thermal-radiation emissivity from surfacesThree block friction set with pine, sandpaper, and felt surfaces in 6 by 3 by 1. 25 inch blocks, each with C hooks at both ends for spring scale pulls on ramps or flat surfaces.