» Demonstration Apparatus for Air Resistance (0805)
Immagini
DESCRIPTION
Exhibit 805 is an apparatus to demonstrate the resistance of air. It consists of two fans with different orientations of the blades, one M with the blades aligned with the direction of rotation and the other M' with the blades rotated out of the plane of rotation. Both fans have collinear axes, each with a toothed gear. The brass mount has two round brass exterior columns and a brass center column of square cross section on which can slide a weight connected to a doubled geared rack in line with the gears on the fan axes. These columns support the gear axes through low-friction pivots. To operate, the weight is lifted to the upper limit of motion of the geared rack and released. In this way both fans turn at the same speed until the weight reaches the lower rest at which point the fan gears are free of the geared rack and turn freely. In air, M turns a lot but M' turns very little due to the air resistance caused by the out-of-line orientation of its blades. Next the same experiment is performed under a glass canopy where the air is removed by a vacuum pump and now the two fans turn the same amount of time.BIBLIOGRAPHY
- [1] J. Salleron "Notice sur les instruments de précision" § 351 pag 327 Paris 1864
Dati Catalografici
| Data di costruzione: | Ignota |
|---|---|
| Data di carico: | Ignota |
| Nr. Inventario: | Ignoto (Ignoto) |
| Costruttore: | Sconosciuta |
| Materiale: | ottone |
| Dimensioni: | Diametro della base: 9,5 cm; Altezza complessiva::20 cm |
| Conservazione: | buono |