1.1 L\u00fd thuy\u1ebft v\u1ec1 hi\u1ec7n t\u01b0\u1ee3ng t\u00e1n s\u1eafc \u00e1nh s\u00e1ng.<\/strong><\/p>\n

a) Hi \u1ec7n t\u01b0\u1ee3ng<\/p>\n

Khi chi\u1ebfu \u00e1nh s\u00e1ng tr\u1eafng \u0111i v\u00e0o m\u1ed9t l\u0103ng k\u00ednh th\u00ec tr\u00ean m\u00e0n ta quan s\u00e1t th\u1ea5y m\u1ed9t d\u00e0i s\u00e1ng li\u00ean t\u1ee5c \u0110\u1ecf, Da cam, V\u00e0ng, L\u1ee5c, Lam, Ch\u00e0m, T\u00edm trong \u0111\u00f3 tia \u0111\u1ecf l\u1ec7ch \u00edt nh\u1ea5t, tia t\u00edm b\u1ecb l\u1ec7ch nhi\u1ec1u nh\u1ea5t.<\/p>\n

Hi\u1ec7n t\u01b0\u1ee3ng t\u00e1n s\u1eafc l\u00e0 hi\u1ec7n t\u01b0\u1ee3ng ph\u00e2n t\u00edch m\u1ed9t ch\u00f9m s\u00e1ng ph\u1ee9c t\u1ea1p th\u00e0nh c\u00e1c ch\u00f9m s\u00e1ng \u0111\u01a1n s\u1eafc kh\u00e1c nhau.<\/p>\n

Gi\u1ea3i th\u00edch hi\u1ec7n t\u01b0\u1ee3ng: Do \u00e1nh s\u00e1ng tr\u1eafng l\u00e0 t\u1eadp h\u1ee3p nhi\u1ec1u \u00e1nh s\u00e1ng \u0111\u01a1n s\u1eafc kh\u00e1c nhau, m\u1eb7t kh\u00e1c v\u00ec chi\u1ebft su\u1ea5t c\u1ee7a l\u0103ng k\u00ednh \u0111\u1ed1i v\u1edbi m\u1ed7i \u00e1nh s\u00e1ng \u0111\u01a1n s\u1eafc l\u00e0 kh\u00e1c nhau do \u0111\u00f3 g\u00f3c l\u1ec7ch sau l\u0103ng k\u00ednh l\u00e0 kh\u00e1c nhau cho n\u00ean c\u00e1c tia l\u00f3 l\u00e0 kh\u00e1c nhau v\u1edbi m\u1ed7i \u00e1nh s\u00e1ng \u0111\u01a1n s\u1eafc. V\u1eady \u00e1nh s\u00e1ng thu \u0111\u01b0\u1ee3c tr\u00ean m\u00e0n l\u00e0 d\u1ea3i s\u00e1ng c\u00f3 m\u00e0u s\u1eafc kh\u00e1c nhau.<\/p>\n

b) \u00c1nh s\u00e1ng \u0111\u01a1n s\u1eafc v\u00e0 s\u1ef1 t\u1ed5ng h\u1ee3p \u00e1nh s\u00e1ng tr\u1eafng<\/p>\n

\u00c1nh s\u00e1ng \u0111\u01a1n s\u1eafc l\u00e0 \u00e1nh s\u00e1ng kh\u00f4ng b\u1ecb t\u00e1n s\u1eafc khi \u0111i qua l\u0103ng k\u00ednh. M\u1ed7i \u00e1nh s\u00e1ng \u0111\u01a1n s\u1eafc c\u00f3 m\u1ed9t m\u00e0u nh\u1ea5t \u0111\u1ecbnh g\u1ecdi l\u00e0 m\u00e0u \u0111\u01a1n s\u1eafc. Khi truy\u1ec1n \u00e1nh s\u00e1ng \u0111\u01a1n s\u1eafc \u0111i qua l\u0103ng k\u00ednh th\u00ec tia s\u00e1ng \u0111i th\u1eb3ng.
\n\u00c1nh s\u00e1ng tr\u1eafng l\u00e0 t\u1eadp h\u1ee3p c\u1ee7a v\u00f4 s\u1ed1 c\u00e1c \u00e1nh s\u00e1ng \u0111\u01a1n s\u1eafc kh\u00e1c nhau c\u00f3 m\u00e0u bi\u1ebfn thi\u00ean li\u00ean t\u1ee5c t\u1eeb \u0111\u1ecf \u0111\u1ebfn t\u00edm.<\/p>\n

\nc) M\u1ed9t s\u1ed1 l\u01b0u \u00fd khi l\u00e0m b\u00e0i t\u1eadp:<\/p>\n

C\u00e1c c\u00f4ng th\u1ee9c t\u00ednh li\u00ean quan \u0111\u1ebfn l\u0103ng k\u00ednh:<\/p>\n

i: g\u00f3c t\u1edbi m\u1eb7t AB.<\/p>\n

j: kh\u00fac x\u1ea1 t\u1ea1i m\u1eb7t AC.<\/p>\n

i1: g\u00f3c kh\u00fac x\u1ea1 \u1edf m\u1eb7t AB. i2: g\u00f3c t\u1edbi m\u1eb7t AC.<\/p>\n

D\u01b0\u1edbi \u0111\u00e2y Th\u1ea7y Nguy\u1ec5n Th\u00e0nh Nam chia s\u1ebb cho c\u00e1c em h\u1ecdc sinh \u00f4n thi THPT Qu\u1ed1c Gia m\u00f4n V\u1eadt L\u00fd v\u1ec1 S\u00f3ng \u00c1nh S\u00e1ng.<\/p>\n