[center][/center][b]Gli specchi sferici[color=#ff7700][br][/color][color=#444444]Alcuni tipi di specchi sono concavi e a causa della loro diversità la luce si protrae in maniera diversa[br][br]Ad esempio, negli specchi parabolici è associato un punto, chiamato [/color][color=#ff7700]fuoco[/color][color=#444444], che ha due proprietà[br][br][br][br][br][/color][/b] [img]https://www.riassuntini.com/fisica/fisica-riflessione-e-specchi-sferici_clip_image002.jpg[/img][br][br][br][br][b]Nella prima proprietà (B), i raggi di una sorgente puntiforme posta nel fuoco[br] e che si riflettono sullo specchio si allontanano in un fascio di raggi paralleli.[br][br][br]Nella seconda proprietà (A), i raggia che arrivano paralleli all'asse di simmetria dello specchio dopo che sono stati riflessi, si intersecano nel fuoco.[br][/b][br][br][br][br][center][color=#ff7700][b]Specchi sferici di piccola apertura[br][br][br][br][/b][/color][/center][center][b][/b][/center][img]data:image/jpeg;base64,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[/img][br][br][b]Caratteristiche:[/b][br][br][b][u][color=#ff7700]Raggio, r;[br][br]Asse ottico che passa per il centro C della sfera e per il vertice V dello specchio;[br][br]La distanza focale f è la distanza tra il fuoco F e il vertice V.[br][/color][/u][/b][br][br][b][color=#ff7700]f=r/2[/color][/b][br][br][br][img]https://encrypted-tbn0.gstatic.com/images?q=tbn%3AANd9GcTbTbYnuWhorfyeCN--QDPFVdXnp8b3YUwmx4VcNWOnqRoQZbl5[/img][br][br][br][color=#ff7700][b]L'immagine è reale se è determinata dall'intersezione dei raggi riflessi, virtuale se è formata dall'intersezione [/b][/color][b]dei loro prolungamenti.[/b][color=#ff7700][b][br][/b][/color]