2017-2018 北师大版七年级数学下册 第三章 变量之间的关系 单元测试题

适用年级:初一
试卷号:637866

试卷类型:单元测试
试卷考试时间:2018/2/20

1.单选题(共9题)

1.
某超市某种商品的单价为70元/件,若买x件该商品的总价为y元,则其中的常量是(    )
A.70B.xC.yD.不确定
2.
变量x与y之间的关系是y=2x-3,当因变量y=6时,自变量x的值是( )
A.9B.15C.4.5D.1.5
3.
根据图示的程序计算变量y的对应值,若输入变量x的值为-1,则输出的结果为( )
A.-2B.2C.-1D.0
4.
某大剧场地面的一部分为扇形,观众席的座位数按下列方式设置:
排数(x)
1
2
3
4

座位数(y)
50
53
56
59

 
有下列结论:①排数x是自变量,座位数y是因变量;②排数x是因变量,座位数y是自变量;③y=50+3x;④y=47+3x,其中正确的结论有(    )
A.1个B.2个C.3个D.4个
5.
在关系式y=5x+3中,有下列说法:①x是自变量,y是因变量;②x的数值可以任意选择;③y是变量,它的值与x的值无关;④用关系式表示的,不能用图象表示;⑤y与x的关系还可以用列表如图象法表示.其中,正确的是(    )
A.①②③B.①②④C.①②⑤D.①④⑤
6.
在利用太阳能热水器来加热水的过程中,热水器里的水温随所晒时间的长短而变化,这个问题中因变量是(  )
A.太阳光强弱B.水的温度C.所晒时间D.热水器
7.
某种签字笔的单价为2元,购买这种签字笔x支的总价为y元,则yx之间的函数关系式为( )
A.y=-xB.y=xC.y=-2xD.y=2x
8.
一列快车从甲地开往乙地,一列慢车从乙地开往甲地,两车同时出发,两车离乙地的路程s(千米)与行驶时间t(小时)的关系如图所示,则下列结论中错误的是(    )

A. 甲、乙两地的路程是400千米 B. 慢车行驶速度为60千米/小时
C. 相遇时快车行驶了150千米 D. 快车出发后4小时到达乙地
9.
李大爷要围成一个矩形菜园,菜园的一边利用足够长的墙,用篱笆围成的另外三边总长应恰好为24米.要围成的菜园是如图所示的矩形ABCD.设BC边的长为x米,AB边的长为y米,则y与x之间的函数关系式是( )

A. y=-2x+24(0<x<12)    B. y=-x+12(0<x<24)
C. y=2x-24(0<x<12)    D. y=x-12(0<x<24)

2.选择题(共4题)

10.下列生物中,属于原核生物的是(  )
11.下列有关溶液的说法错误的是(   )

①碘酒中的溶质是酒精

②改变条件,饱和溶液与不饱和溶液可相互转化

③饱和溶液一定是浓溶液

④乳化后形成的乳液与溶液同样稳定

⑤氢氧化钠溶于水液体温度会升高.

12.

阅读理解

      What would the world be like if cars could drive themselves? Imagine seeing an empty car passing by on its way to pick up its owner, or a car full of passengers who are reading, listening to music or even sleeping. But none of them are worried about the road ahead.

      Well, all of this could be the future of driving. There are several companies, including Google, working on driverless cars. So far, no Google self-driven car has gotten a traffic ticket, but some of them have been in accidents when other cars hit them.

      These cars are now still in the testing stages. But, if the tests are successful, these electric self-driven cars could be put into use very soon.

      The cars already have many features(特点)allowing them to take the place of drivers during certain situations. Some features include cars being able to park themselves, or slow down when they notice objects close by. They can also control the speed if there are dangerous conditions.

      Scientists and engineers believe, with the help of wireless signals, cameras and GPS, we are now at a stage where creating a safe self-driven car might be possible.

      The cause of deadly road accidents is usually careless drivers or dangerous conditions. The self-driven car may be able to prevent these. However, some people do not like the idea. American lawyer Whit Drake, for example, doesn't believe these cars are safe. He thinks that technologies can also be mistakes.

13.

阅读理解

      What would the world be like if cars could drive themselves? Imagine seeing an empty car passing by on its way to pick up its owner, or a car full of passengers who are reading, listening to music or even sleeping. But none of them are worried about the road ahead.

      Well, all of this could be the future of driving. There are several companies, including Google, working on driverless cars. So far, no Google self-driven car has gotten a traffic ticket, but some of them have been in accidents when other cars hit them.

      These cars are now still in the testing stages. But, if the tests are successful, these electric self-driven cars could be put into use very soon.

      The cars already have many features(特点)allowing them to take the place of drivers during certain situations. Some features include cars being able to park themselves, or slow down when they notice objects close by. They can also control the speed if there are dangerous conditions.

      Scientists and engineers believe, with the help of wireless signals, cameras and GPS, we are now at a stage where creating a safe self-driven car might be possible.

      The cause of deadly road accidents is usually careless drivers or dangerous conditions. The self-driven car may be able to prevent these. However, some people do not like the idea. American lawyer Whit Drake, for example, doesn't believe these cars are safe. He thinks that technologies can also be mistakes.

3.填空题(共8题)

14.
在求补角的计算公式y=180°-x中,变量是____,常量是_____.
15.
“早穿皮袄,午穿纱,围着火炉吃西瓜”这句谚语反映了我国新疆地区一天中,_____随____变化而变化,其中自变量是___,因变量是___.
16.
若一个长方体底面积为60cm2,高为hcm,则体积V(cm3)与h(cm)的关系式为_____,若h从1cm变化到10cm时,长方体的体积由___cm3变化到___cm3.
17.
李老师带领x名学生到某动物园参观,已知成人票每张20元,学生票每张10元.设门票的总费用为y元,则y=________.
18.
如图所示表示“龟兔赛跑”时路程与时间的关系,已知龟、兔上午8点从同一地点出发,请你根据图中给出的信息,算出乌龟在___点追上兔子.
19.
某种储蓄的月利率是0.2%,存入100元本金后,不扣除利息税,本息和y(元)与所存月数x(x为正整数)之间的关系为__________,4个月的本息和为________.
20.
如图①,在直角梯形ABCD中,动点P从点B出发,沿BC、CD运动至点D停止,设点P运动的路程为x,△ABP的面积为y.若y关于x的函数图象如图②所示,则△BCD的面积是__.
21.
如图,是小明从学校到家里行进的路程s(米)与时间t(分)的函数图象.观察图象,从中得到如下信息:
①学校离小明家1000米;
②小明用了20分钟到家;
③小明前10分钟走了路程的一半;
④小明后10分钟比前10分钟走得快,
其中正确的有_____(填序号).

4.解答题(共7题)

22.
从有关方面获悉,在我市农村已经实行了农村新型合作医疗保险制度.享受医保的农民可在规定的医院就医并按规定标准报销部分医疗费用.下表是医疗费用报销的标准:
医疗费用范围
门诊
住院
0~5000元
5001~20000元
20000元以上
每年报销比例标准
30%
30%
40%
50%
 
(说明:住院医疗费用的报销分段计算.如:某人住院医疗费用共30000元,则5000元按30%报销、15000元按40%报销、余下的10000元按50%报销;题中涉及的医疗费均指允许报销的医疗费).
(1)某农民2016年在门诊看病共报销医疗费180元,则他在这一年中门诊医疗费用共________元;
(2)设某农民一年中住院的实际医疗费用为x元(5001≤x≤20000),按标准报销的金额为y元,试求出y与x的关系式;
(3)若某农民一年内本人自付住院医疗费17000元(自付医疗费=实际医疗费-按标准报销的金额),则该农民当年实际医疗费用共多少元?
23.
如图棱长为a的小正方体,按照下图的方法继续摆放,自上而下分别叫第一层、第二层…第n层,第n层的小正方体的个数记为S.解答下列问题:

n
1
2
3
4

S
1
3
 
 

 
(1)按要求填写上表:
(2)研究上表可以发现S随n的变化而变化,且S随n的增大而增大有一定的规律,请你用式子来表示S与n的关系,并计算当n=10时,S的值为多少?
24.
某商场经营一批进价为a元/台的小商品,经调查得如下数据:
销售价(x元/台)
35
40
45
50
日销售量(y/台)
57
 
27
 
日销售额(t/元)
 
1680
 
600
 
(1)请在表中空白处填上适当的数;
(2)用语言描述日销售量y和日销售额t随销售价x变化而变化的情况.
25.
温度的变化是人们经常谈论的话题,请根据图象与同伴讨论某天温度变化的情况.
(1)这一天的最高温度是多少?是在几时到达的?最低温度呢?
(2)这一天的温差是多少?从最低温度到最高温度经过多长时间?
(3)在什么时间范围内温度在上升?在什么时间范围内温度在下降?
26.
科学家研究发现,声音在空气中传播的速度y(米/秒)与气温x(°C)有关,当气温是0°C时,音速是331米/秒;当气温是5°C时,音速是334米/秒;当气温是10°C时,音速是337米/秒;气温是15°C时,音速是340米/秒;气温是20℃时,音速是343米/秒;气温是25°C时,音速是346米/秒;气温是30°C时,音速是349米/秒.
(1)请你用表格表示气温与音速之间的关系;
(2)表格反映了哪两个变量之间的关系?哪个是自变量?哪一个是对应的值?
(3)当气温是35°C时,估计音速y可能是多少?
(4)能否用一个式子来表示两个变量之间的关系?
27.
某机动车出发前油箱内有油42L.行驶若干小时后,途中在加油站加油若干升.油箱中余油量Q(L)与行驶时间t(h)之间的关系如图所示,根据图象回答问题.

(1)机动车行驶几小时后加油?
(2)中途加油________L;
(3)如果加油站距目的地还有240km,车速为40km/h,要到达目的地,油箱中的油是否够用?并说明原因.
28.
汽车在山区行驶过程中,要经过上坡、下坡、平路等路段,在自身动力不变的情况下,上坡时速度越来越慢,下坡时速度越来越快乐,平路上保持匀速行驶,如图表示了一辆汽车在山区行驶过程中,速度随时间变化的情况.
(1)汽车在哪些时间段保持匀速行驶?时速分别是多少?
(2)汽车遇到了几个上坡路段?几个下坡路段?在哪个下坡路段上所花时间最长?
(3)用自己的语言大致描述这辆汽车的行驶情况,包括遇到的山路,在山路上的速度变化情况等.
试卷分析
  • 【1】题量占比

    单选题:(9道)

    选择题:(4道)

    填空题:(8道)

    解答题:(7道)

  • 【2】:难度分析

    1星难题:0

    2星难题:0

    3星难题:0

    4星难题:0

    5星难题:0

    6星难题:16

    7星难题:0

    8星难题:6

    9星难题:2