light

 Traveling Light 

Light travels very fast-much faster than sound. That's why you see a flash of lightning before you hear the sound of thunder, even though both happen at exactly the same time. 

Light travels in straight lines. A flashlight's beam shows this. If you shine a flashlight on a wall, you can mark where its beam of light hits. The distance from the mark back to the flashlight is always a straight line.

Traveling light rays react differently when they reach different types of materials. Transparent materials allow all light rays to travel through them. Translucent materials allow some light to shine through them. Frosted glass, stained-glass windows, and dark sunglasses are translucent. Opaque materials, such as doors, walls, and our bodies, block out all light rays. Opaque materials absorb and reflect light.

Vocabulary:

shine                    :            chiếu sáng

beam                    :            chùm tia

distance                :            khoảng cách

rays                      :             tia sáng

react                     :             phản ứng

opaque                 :             mờ mịt

absorb                  :             hấp thụ

reflect                   :            phản ánh

23/8/2021

Levic