DEVICE FOR MODEL DEMONSTRATION OF FERMA PRINCIPLE Russian patent published in 1995 - IPC

FIELD: optics; demonstration optical devices. SUBSTANCE: unit for imitating two media and their border is made in form of guides for ball, which imitates light particles. Guides are made in form of several transparent pipes, filled with liquid. The pipes are closed at both their ends and mounted at the same vertical plane. At least, two pipes have two units, which are disposed at some angle one to the other. Top ends, vertexes and lower ends of the pipes belong to three horizontal lines. Distances between top and lower ends of any pipes are equal. Internal diameters of top and lower parts of the pipes are chosen in such a manner, that ball movement speeds in them be equal to V₁ and V₂ correspondingly. One pipe is made with relation sinα/sinb= V₁/V₂, where α and b angles of slopes of top and lower parts to the vertical line. EFFECT: improved efficiency. 2 cl, 1 dwg