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Category: Geometry

If-we-observe-when-light-source-illuminates-the-surface-of-an-object-lets-say-its-a-sphere-football-the-area-visible-zone-decreases-as-the-light-source-comes-near-the-surface-So-calculate-rate-of-

Question Number 210265 by BHOOPENDRA last updated on 04/Aug/24 $${If}\:{we}\:{observe}\:{when}\:{light}\:{source}\: \\ $$$${illuminates}\:{the}\:{surface}\:{of}\:{an}\:{object} \\ $$$${lets}\:{say}\:{its}\:{a}\:{sphere}\left({football}\right)\:,{the}\:{area} \\ $$$${visible}\:{zone}\:{decreases}\:{as}\:{the}\:{light}\:{source} \\ $$$${comes}\:{near}\:{the}\:{surface}.{So}\:\:{calculate}\:{rate}\:{of}\:{change} \\ $$$${visible}\:{area}\:{when}\:{light}\:{source}\:{is}\:{coming} \\ $$$${towards}\:{the}\:{object}\:{or}\:{moving}\:{away}\: \\ $$$${from}\:{the}\:{object}.{And}\:{in}\:{the}\:{case}\:{of}\:{earth} \\…

Question-210172

Question Number 210172 by efronzo1 last updated on 01/Aug/24 Answered by a.lgnaoui last updated on 02/Aug/24 $$\frac{\mathrm{sin}\:\mathrm{2}\boldsymbol{\mathrm{a}}}{\boldsymbol{\mathrm{BE}}}=\frac{\mathrm{cos}\:\boldsymbol{\mathrm{a}}}{\boldsymbol{\mathrm{AB}}}\:\:\:\:\left(\measuredangle\mathrm{AED}=\mathrm{90}−\mathrm{2a}\right) \\ $$$$\mathrm{AB}=\frac{\mathrm{DEcos}\:\boldsymbol{\mathrm{a}}}{\mathrm{sin}\:\mathrm{2}\boldsymbol{\mathrm{a}}}.=\frac{\boldsymbol{\mathrm{BE}}}{\mathrm{2sin}\:\boldsymbol{\mathrm{a}}} \\ $$$$\boldsymbol{\mathrm{Aire}}\left(\boldsymbol{\mathrm{ABC}}\right)=\boldsymbol{\mathrm{Air}}\mathrm{e}\left(\boldsymbol{\mathrm{ADFC}}\right)+\boldsymbol{\mathrm{Aire}}\left(\boldsymbol{\mathrm{DBF}}\right) \\ $$$$\boldsymbol{\mathrm{A}}\mathrm{ire}\left(\mathrm{BDE}\right)=\mathrm{Aire}\left(\boldsymbol{\mathrm{BEF}}\right)+\boldsymbol{\mathrm{Aire}}\left(\boldsymbol{\mathrm{BDF}}\right) \\ $$$$\Rightarrow\:…