问题 填空题

当光垂直平面镜镜面入射时,入射角等于______度;当入射光线和平面镜的夹角为20度时,反射角为______度.

答案

因为入射光线垂直射到平面镜上,入射光线和法线重合,所以入射角等于0°,而反射角等于入射角,即反射角为0°.

因为入射光线与平面镜的夹角是20°,所以入射角为90°-20°=70°,而反射角等于入射角,即反射角为70°.

故答案为 0,70.

材料分析题

青春是美好的,令人神往,令人怦然心动!青春也是短暂的,她对每个人自由一次,最终也如梦似烟,一丝一缕地散去而不再飘回,青春的意义和价值在于有所追求,并为之奋斗过。 青春是美丽的,但美丽的标准绝不是漂亮的服饰,时髦的打扮和所谓的潇洒浪漫。有理想、有道德、有知识、有修养是美丽青春不可能缺少的内容。

(1)从材料中你体会到青春是怎样的?

                                                                                                                                                              

                                                                                                                                                              

                                                                                                                                                              

(2)谈谈你要怎样珍惜青春,开采青春的价值。

                                                                                                                                                              

                                                                                                                                                              

                                                                                                                                                               

单项选择题 A1型题