Mei Ling memasukkan straw ke dalam segelas air. Straw itu kelihatan bengkok di permukaan air, walaupun sebenarnya lurus. Mengapakah ini berlaku?
光的折射 = pembiasan cahaya
光从一种物质进入另一种物质,例如从空气进入水,前进的方向会改变,这叫折射。这个单元学习折射现象、彩虹怎样形成,以及光的性质在生活中的用途。
例子:吸管放进水杯,在水面处看起来像折断了。
注意:吸管本身没有弯,是光的方向改变了。
refraction of light = pembiasan cahaya
When light passes from one medium into another, such as from air into water, its direction changes; this is refraction. This unit covers refraction, how rainbows form and how the properties of light are used in daily life.
Example: a straw in a glass of water looks broken at the surface.
Watch out: the straw is not bent; the light changes direction.
Kenali
Apakah pembiasan cahaya?
Pembiasan cahaya ialah perubahan arah pergerakan cahaya apabila melalui dua medium yang berbeza, contohnya udara dan air.
Contoh: Kolam renang kelihatan lebih cetek daripada kedalaman sebenar.
what refraction is = apakah pembiasan
Refraction is the change in direction of light passing through two different media (medium), such as air and water. Objects in water therefore look shifted or bent.
Example: a swimming pool looks shallower than it is, so take care before jumping in.
Watch out: reflection bounces light back; refraction bends it as it passes through.
matching phenomena = padankan fenomena
A straw looking bent in water is light changing direction between two media; seeing your face in a mirror is light bouncing back; a shadow is straight-moving light being blocked.
Example: a fish looking shallower than it is also shows refraction.
Watch out: keep reflection and refraction apart.
Fahami
Pembentukan pelangi
Pelangi terbentuk apabila cahaya Matahari dibiaskan oleh titisan air hujan. Cahaya putih terurai kepada tujuh warna.
Contoh: Pelangi biasanya kelihatan selepas hujan apabila Matahari berada di belakang kita.
how rainbows form = pembentukan pelangi
After rain the air has many tiny water droplets. Sunlight is refracted as it passes through them, splitting white light into seven colours to form a rainbow. A basin of water and a mirror can also make a small rainbow.
Example: we often see a rainbow after rain when the Sun is behind us.
Watch out: a rainbow needs both sunlight and water droplets.
what a rainbow needs = keperluan pelangi
A rainbow comes from refracted light. It needs light and something for the light to pass through. What is that?
Example: spraying a hose in sunlight can make a small rainbow.
Watch out: no sunlight at night means no rainbow.
Fahami
Kepentingan sifat cahaya
Sifat cahaya membantu manusia mencipta alat optik seperti kanta tangan, binokular, cermin mata dan periskop.
Contoh: Kanta tangan menggunakan pembiasan cahaya untuk membesarkan imej serangga kecil.
importance of light properties = kepentingan
People use the straight-line movement, reflection and refraction of light to invent optical tools (alat optik) such as magnifying glasses (kanta tangan), binoculars (binokular), spectacles and periscopes.
Example: a magnifying glass uses refraction to enlarge a small insect.
Watch out: magnifiers use refraction; periscopes use reflection.
Fikir
Sifat cahaya manakah digunakan oleh kanta tangan?
放大镜的原理 = prinsip kanta
光是穿过放大镜的玻璃,还是被它弹回来?穿过时转了方向,是哪一种性质?
例子:眼镜也是让光穿过镜片。
注意:镜子才是反射。
how a magnifier works = prinsip kanta
Does light pass through the lens or bounce off it? Changing direction while passing through is which property?
Example: spectacles also let light pass through the lenses.
Watch out: mirrors are the ones that reflect.
Ringkasan
Syabas!
Pembiasan cahaya
Pembiasan ialah perubahan arah cahaya apabila melalui dua medium berbeza. Pelangi terbentuk apabila cahaya Matahari dibiaskan oleh titisan air. Sifat cahaya digunakan dalam alat optik.