问题 应用设计题

(1)画出图7中入射光线经平面镜反射后的反射光线.

(2)根据图8中的入射光线作出相应的折射光线.

答案

分析:(1)在反射现象中,反射光线、入射光线分居法线两侧,反射角等于入射角;画反射光线,要根据光的反射定律,先做出法线,然后根据两角相等画出.

(2)根据凸透镜对光线的作用:过焦点的光线经凸透镜折射后折射光线平行于主光轴;平行于主光轴的光线经凸透镜折射后折射光线通过焦点,画出两条入射光线的折射光线.

解答:解:(1)过入射点画出法线,法线与镜面垂直,并且用虚线表示;根据光的反射定律,反射光线如图所示:

(2)平行于主光轴的光线折射光线通过焦点画;过焦点的入射光线折射光线平行于主光轴画,如图所示:

阅读理解
We humans live in different parts of the world, but we have the same “mother”. She gives us everything we need in our daily life. She is our Mother Earth. Everybody wants to live in a green city. A green city is a healthy and pleasant place for people to live in. It can get its energy from something like solar and wind power. Also, it is connected by clean public transportation.
The Hyperloop (超级高铁)
The Hyperloop is a high-speed transportation. It works by having capsules (舱) with passengers in. The capsules run on the air. The Hyperloop plans to run from Los Angeles to San Francisco. With an average speed of 962 km per hour, it is only 35 minutes between the two cities. The solar panels (板) provide power to the Hyperloop.
Smart Wheel
Smart Wheel is a bicycle wheel with a motor. This invention can easily fit onto almost any bike. And the motor allows bikes to travel up to 50km once. Smart Wheel is different from other electric bikes. It can be controlled through your smartphone’s Bluetooth. The smartphone can show your speed, distance and travel time.
Solar Sidewalk (太阳能步道)
George Washington University made a special path in 2013. The path is about 9 square meters. It is covered with solar panels that can provide energy to power 450 LED lights. These lights can light the walkway after dark. The solar panel is also strong enough for people to walk on.
小题1:A green city is ________.
A.clean and tidyB.full of plants
C.healthy and pleasantD.rich for energy
小题2:It is ________ from Los Angeles to San Francisco.
A.About 962 km.B.About 560 km.
C.About 700 km.D.About 450 km.
小题3:About Smart Wheel, which is Not right?
A.It can travel 50km once.
B.It can fit onto almost any bike.
C.It’s a motorbike with a bicycle wheel.
D.The smartphone’s Bluetooth can control it.
小题4:What can solar panels do?
A.They can run on the air.B.They can provide energy.
C.They can carry passengers.D.They can show your travel time.
小题5:What do you think of the public transportation?
A.Modern and clean.B.Green and dangerous.
C.Exciting and crazy.D.Expensive and impossible.
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