问题 问答题

电动自行车是倍受人们青睐的一种交通工具.电动骑行时,蓄电池对车上电动机供电,电动机为车提供动力.下表是某型号电动自行车主要技术参数.

⑴行驶过程中每个轮胎与地面的接触面积为50cm2,当一个质量为5 0Kg的中学生骑着该电动自行车在平直的公路上行驶时,地面受到的压强是多大?(取g="10N/" kg)

⑵若蓄电池储存能量的80%用于电动自行车行驶克服阻力做功,电动自行车在平直公路上匀速行驶时受到的平均阻力为40N,蓄电池充满一次电最多能连续电动行驶多远?

(3)从环保的角度,与摩托车相比,电动自行车有什么优缺点?(各举一条)

答案

⑴0.9×105Pa⑵ m(3)见解析

⑴地面受 到的压强:P="F/S" =(40㎏+50㎏)×10N/㎏/0.01m2=0.9×105Pa

⑵蓄电池储存的电能:W=0.576kw·h=2073600J

因蓄电池储存能量的80%用于电动自行车行驶克服阻力做功:2073600J×80%="FS"

所以,电动自行车能连续电动行驶的路程:S = m

(3)优点:无尾气.噪音小.缺点 :蓄电池一般使用一年左右就需更换,废弃后 的电池污染境

(1)由表中参数可知电动车的最大车速,利用速度公式求出小刘从家到单位的最少时间;

(2)地面受到的压力等于电动车和人的重力之和,根据公式,可求地面受到的压强;

(3)电动自行车无尾气,噪音小,但蓄电池需常更换,废旧蓄电池污染环境.

本题借助电动自行车考查速度公式的应用、压强的计算以及能源的利用和对环境的污染,学生在计算第(2)问时容易忽略电动车的质量,这是需要注意的地方.

【考点】压强的大小及其计算;功率计算公式的应用.

阅读理解

Would the voice of Amanda Holden saying “your city had talent” encourage you to use a litter bin? Or maybe former Monty Python star Michael Palin telling you no one had expected “the Spanish bin-quisition”?

Organizers of a plan persuading celebrities(名人)to lend their voices to “talking bins”believe it can make a real difference to keeping Britain tidy. They hope that by using humor, they will succeed where fines and warnings have failed in keeping streets and parks clean.

A similar experiment in Sweden found a talking bin received nearly three times as much rubbish as an ordinary one because people were attracted by its quality of being new and unusual value.

Twenty-five specially adapted bins to be installed(安装)in the streets of London and Liverpool next  month will use a sound card to play a themed message when litter is placed inside. For example,one near the Royal Opera House will play a “thank-you” message sung by Janis Kelly to the tune of Nessun Dorina. Bins installed in Liverpool will play Beatles-themed messages. For others,Britain’s Got Talent  judge Holden is expected to record the message:“This is Amanda, and this city’s got talent.”

The campaign,entitled Bin Thinking, is being organized by art group Sing London. If successful,talking bins could become a familiar feature on Britain’s streets.

Colette Hiller, director of Sing London, said, “ The idea is to reward people in a small way for changing their behavior and raise awareness through a sense of fun.”

小题1:What is the plan persuading celebrities to lend their voices to “talking bins” aimed at?

A.Attracting passers’-by attention on celebrities.

B.Encouraging people to use the litter bins to keep Britain tidy.

C.Making fun of those who won’t keep the streets and parks clean.

D.Thanking people for cleaning the litter bins through a sense of fun.小题2:The following stars’ voices are to be lent to “talking bins” except_________________.

A.Amanda Holder’ s

B.Michael Palin’s

C.Janis Kelly’s

D.Nessun Dorma' s小题3:We can infer from the text that_________________.

A.children are most attracted by “talking bins”

B.different messages will be played due to different streets

C.Britain is the first city where the experiment on “talking bins” was made

D.“talking bins” might take the place of ordinary litter bins in Britain小题4:What would be the best title for the text?

A.Lending your voice to “talking bins”

B.Sing London art organization

C.A campaign named Bin Thinking

D.A new experiment on litter bins

单项选择题