MIDDLE YEAR PROGRANMME GRADE 8 PHYSICS FIRST SEMESTER Class: Name: Number: Mark 1. The diagram shows a ray of light in air incident on a glass block. Some of the light is refracted, and some of the light is reflected. Two angles p and q are marked on the diagram. Which row gives the angle of incidence and shows whether the ray undergoes total internal reflection? ( 2. Which diagram correctly shows a ray of light reflected by a plane mirror? ) ( ) 3. The diagram shows a ray of light incident on the edge of a piece of glass. The angle i is greater than the critical angle. Which arrow shows the direction of the ray after it leaves the edge of the glass? ( 1 ) MIDDLE YEAR PROGRANMME GRADE 8 PHYSICS FIRST SEMESTER Class: Name: Number: Mark 4. 当光从透明介质斜射入空气时折射光线将_______________,(选填靠近法线或偏离法 线)这时折射角________于入射角 5. 当光线垂直与水面入射时,入射角大小为________,反射角大小为_________,折射角大 小为_________,光射入水中,光速将________(选填变大或变小或不变) 6. 古诗词中有许多描述光学现象的诗句,如“潭清疑水浅”说的就是光的_______现象; “池水映明月”说的就是光的________现象 7. 如图所示,水平桌面上斜放着一个平面镜,桌面上有一个小球向镜面滚去.要使平面镜 中小球的像沿竖直方向下落,则镜面与桌面间的夹角为应为______度 8. 乐音的三要素是________、_________和________,其中________与频率有关,________ 与发声体的振幅和距发声体的远近有关,________与发声体本身结构有关。 9. 如图所示,是一束光线斜射到空气和某种物质的界面上的情况.________是入射光线, ________是折射光线,________是界面,界面的________边是空气 10.两座高山相距340米,某人站在两山之间某处高喊一声,他听到两次回声的时间差为1 秒,试求人与其中一座山的距离(声速取340米/秒) 2