问题 解答题
弹簧挂上物体后会伸长,已知一弹簧的长度(cm)与所挂物体的重量(kg)之间的关系如下表:
所挂物体的重量(kg)
0
1
2
3
4
5
6
7
弹簧的长度(cm)
12
12.5
13
13.5
14
14.5
15
15.5
(1)当所挂物体的重量为3kg时,弹簧的长度是_____________cm;
(2)如果所挂物体的重量为xkg,弹簧的长度为ycm,根据上表写出y与x的关系式;
(3)当所挂物体的重量为5.5kg时,请求出弹簧的长度。
(4)如果弹簧的最大伸长长度为20cm,则该弹簧最多能挂多重的物体?
答案

(1)13.5 (2)y=12+0.5x (3)14.75cm (4)16千克

题目分析:解:(1)观察所给的图表得,当当所挂物体的重量为3kg时,弹簧的长度=13.5:   

(2)如果所挂物体的重量为xkg,弹簧的长度为ycm ,根据表中数据可得出弹簧的长度(cm)与所挂物体的重量成正相关关系,所以设y与x的关系式为,当x=0,y=12;当x=2,y=13,即,解得,所以y与x的关系式为y=12+0.5x;   

(3)当x=5.5时,y=12+0.5×5.5=14.75cm; 

(4)当y=20时,得20=12+0.5x,解之得x=16千克。 

点评:本题考查一次函数,解答本题的关键是要求考生掌握待定系数法,会用待定系数法求一次函数的关系式

填空题

[A] He is unlikely to produce such a big hit in the near future, so more of his attention is directed to revising the old song and selling it to more people.

[B] Back in the 1950s, he says, performers got only one-tenth of the share of royalties that they do now. For years, artists have, with good reason, accused big record labels of ripping them off.

[C] This month, early recordings by Elvis himself started to enter Europe’s public domain. Over the next few decades a torrent of the most popular tracks from the Beatles, the Rolling Stones and many other artists will become public property in Europe—to the pleasure of fans and the consternation of the music industry.

[D] The music industry also points out that America gives artists almost twice as much copyright protection as Europe. America has repeatedly lengthened copyright terms, with the latest reprieve, the Sonny Bono Copyright Term Extension Act of 1998, giving performers protection for 95 years after publication.

[E] But when the attention is shifted from Europe to America, artists should feel much better because the length of copyright protection there is even shorter. It seems that the American government is more interested in serving the public than the already very rich artists.

[F] Music executives want the European Commission to protect them from such unwelcome come competition by extending the copyright term.

[G] And that estimate accounts only for songs up to the end of the 1950s. Far more will be at risk as music from the 1960s and 1970s moves out of copyright.

"Every three months from the beginning of 2008," says Cliff Richard, who was once Britain’s answer to Elvis Presley, "I will lose a song." The reason is that in most European countries copyright protection on sound recordings lasts for 50 years, and (now) Sir Cliff recorded his first hit single, "Move It", in 1958. (41) ______

One of the big four music firms estimates that about 100m "deep catalogue" (ie, old) albums now sold in Europe each year will have entered the public domain by the end of 2010. Assuming a current wholesale price of $10, that could jeopardise $1 billion of revenues, or about 3% of annual recorded music sales. (42)______

Even once much of the back catalogue has entered the public domain, the big music firms can carry on selling it on CD. They will even benefit from not having to pay anything to the artist or to his estate. They will in many cases still own copyright on the original cover art. But they will face new competition from a host of providers of CDs who may undercut them. And on the internet, public domain music is likely to be free, as much of the copyrighted stuff already is on peer-to-peer networks.

(43)______Artists have rallied to the cause: U2, Status Quo and Charles Aznavour all want the 50-year limit increased. Many more acts will sign a petition this spring. Sir Cliff has spent hours complaining to the commission that composers of songs get copyright for 70 years after their death: more than performers.

(44)______

Many people believe that America has gone too far in protecting copyright at the expense of the public good, including, it seems, the commission, which said last year that it saw no need to lift its own 50-year limit. Its deadline for proposals on copyright law has slipped from this year to 2006. But governments are likely to weigh in on the issue. France, Italy and Portugal have indicated that they support an extension of the term, and Britain is likely to stick up for its own music major, EMI.

Although artists and their estates want longer copyright, the big music firms would benefit from it the most, especially in the next couple of decades, says Stephen King, chairman of the Association of United Recording Artists and manager of the Libertines. (45)______ Now they have wised up about making deals. The best guarantee of financial security—safer than clinging on to copyright—is hiring a good lawyer early on.

45()

判断题