驼峰专用无源型车轮传感器适应的车速范围为()。
A:3~30km/h B:0~30km/h C:3~50kmh D:0~60km/h
在一个标准大气压下,能反映水在均匀加热过程中,水的温度随加热时间变化的函数图象大致是( )
A:
B:
C:
D:
观察下列图形,根据提供信息填空;
△DGO≌△
△ATQ≌△
△RBE≌△
△KMH≌△
(1)观察△ODG和△ART可知D、G、O的对应点分别为R、T、A,故填:RTA;
(2)观察△ATQ和△OCM可知A、T、Q的对应点分别为M、C、O,故填:MCO;
(3)观察△BRE和△BGE可知R、B、E的对应点分别为G、B、E,故填:GBE;
(4)观察△KMH和△KDH可知K、M、H的对应点分别为H、D、K,故填:HDK;
某单位鼓励职工节约用电.规定每月职工用电收费标准为20kwh以内按0.2元/kmh计算,超过20的按0.50元/kmh计算.现已知某职工某月用电15kmh,那么他这个月应该交费多少钱?另一位职工因为经常忘记关电脑,用电量达到28kmh,那么他应该交多少电费?
解:0.2×15=3(元)
0.2×20+0.5×(28﹣20)
=4+0.5×8
=4+4
=8(元)
答:某职工某月用电15kmh,他这个月应该交费3元钱;另一位职工因为经常忘记关电脑,用电量达到28kmh,他应该交8元电费.
毕节市国家级风景名胜区九洞天是一段长约6公里的地下河,因头上开有九个“天窗”(洞口)得名“九洞天”,如图所示.划船游览沿途风光时发现头上“天窗”会向后退是以 为参照物;游经最具代表性的五、六、七洞天时,万千岩燕穿插翩飞其间,“喃呢”之声不绝于耳,能分辨不同岩燕的“喃呢”之声是依据声音的 ;若游船的平均速度为3.6kmh,则游完全程约需 .(结果保留小数点后一位)

解:
(1)游客划船游览沿途风光时,以船或游客为参照物时,船和船上的游客与“天窗”(洞口)的相对位置在不断发生变化,所以看到头上“天窗”会向后退;
(2)不同的发声体发出声音的音色不同,故游客能分辨不同岩燕的“喃呢”之声是依据声音的音色;
(3)根据v=[7f03ed65e3130696.png]可知,游完全程需要的时间为:
t=[38646ed2fb14d0bb.png]=[3edb38a09aac55a6.png]≈1.7h.
故答案为:船或船上的游客;音色;1.7h.
一辆沿着平直公路行驶的汽车,它的速度在5s内从43.2km/h增加到64.8km/h,通过的路程是70m,则这辆车在5s内的平均速度为( )
A:50.4km/h B:54kmh C:21.6kmh D:36km/h
有关部门规定在一般公路上正常行驶的汽车速度不能超过80kmh.某一在平直路面上以72km/h速度匀速行驶的汽车,刹车后做匀减速直线运动,经过4s速度减小为36kmh,求:
(1)刹车后5s末汽车的速度大小;
(2)刹车后10s内汽车的位移大小,
解:(1)速度v1=72km/h=20m/s,v2=36km/h=10m/s,
根据加速度定义可知:a=[8f366c4017929d54.png]=﹣2.5m/s2,汽车的加速度为﹣2.5m/s2与汽车运动方向相反;
汽车做匀减速直线运动,速度减为0的时间为:t0=[8845db0963be1869.png]=[5871b138c5a1c77a.png]=8s
汽车5s末的速度大小为:v=v1+at2═20﹣2.5×5=7.5m/s;
(2)因10>t0=8s,则可由速度位移公式得:x=[a2f166314bb43447.png]=[2b53821667f6699e.png]=80m;
答:(1)刹车后汽车6s末的速度大小为7.5m/s;
(2)刹车后汽车10s内的位移大小为80m
A:全长66km属于位移
B:起点速度95kmh属于瞬时速度
C:该汽车全程的平均速度是92.5km/h
D:该汽车没有超速
火车从A站驶往B站,途中经过一铁路桥,若火车过桥最高限速为72kmh,火车减速前的速度为288km/h,火车减速行驶30s,恰好以最高限速通过铁路桥,火车减速过程中的加速度大小为( )
A:0.5m/s2 B:1m/s2 C:2m/s2 D:7.2m/s2
阅读理解;阅读下面的短文,从每小题所给的A.、B.、C.、D.四个选项中,选出最佳选项。
Time zone:
Eastern Standard Time(EST): GMT+ 10 hours.
There is no daylight saving time in QueenslanD.
Legal drinking age:
18 years and older. Always keep your ID with you to prove your agE.
Alcohol (酒) shops & hotels are the only places where alcohol can be bought.
Dangers:
Dial 000 from a fixed line or 112 from a mobile phonE. Police, ambulance, firE.
Electricity:
240/250 volts AC 50Hz Universal outlets for 110 volts (shavers only) standard in hotels, apartments, motels.
Telephones:
Australian international code is 61.
Road rules:
Left hand side driving. There is a 50kmh speed limit in most living areas and on open highways100-110kmh. Seat belts must be worn all the timE. If you want to hire a car, take along your driver's licensE.
No smoking:
Indoors: Indoor areas are no smoking.
Poker Machines: Poker machine areas are no smoking.
Outdoors: Non-enclosed eating and drinking areas are no smoking.
Swimming Safety:
ALWAYS SWIM BETWEEN THE RED AND YELLOW FLAGS and pay attention to the life guards' advicE. Gold Coast beaches are guarded by skilled life guards and volunteers at weekends.
1. The above information is most probably taken from a (an) _____.
A. science magazine B. education newspaper
C. travel guidebook D. horror novel
2. We can learn from the above information that in Queensland _____.
A. smoking is not allowed in lots of places
B. people can buy alcohol anywhere with ID
C. people can swim beyond the red and yellow flags
D. when a building is on fire, dial 112 from a fixed line
3. If Mr Black is having a holiday in Queensland, he can _____.
A. drive on the right hand side
B. hire a car with his driver's license
C. drive at the speed of 120kmh on highways
D. drive his car without wearing the seat belt
1C 2A 3B