(18分)如右图所示,在竖直面内有一个光滑弧形轨道,其末端水平,且与处于同一竖直

题型:计算题

问题:

(18分)如右图所示,在竖直面内有一个光滑弧形轨道,其末端水平,且与处于同一竖直面内光滑圆形轨道的最低端相切,并平滑连接。A、B两滑块(可视为质点)用轻细绳拴接在一起,在它们中间夹住一个被压缩的微小轻质弹簧。两滑块从弧形轨道上的某一高度由静止滑下,当两滑块刚滑入圆形轨道最低点时拴接两滑块的绳突然断开,弹簧迅速将两滑块弹开,其中前面的滑块A沿圆形轨道运动恰能通过轨道最高点。已知圆形轨道的半径R=0.50m,滑块A的质量mA=0.16kg,滑块B的质量mB=0.04kg,两滑块开始下滑时距圆形轨道底端的高度h=0.80m,重力加速度g取10m/s2,空气阻力可忽略不计。

试求:(1)A、B两滑块一起运动到圆形轨道最低点时速度的大小;

(2)滑块A被弹簧弹开时的速度大小;

(3)弹簧在将两滑块弹开的过程中释放的弹性势能。

考点:机械能守恒定律
题型:计算题

对球根花卉,通常采用()的播种方式。

A.条播

B.扦插

C.散播

D.点播

题型:计算题

碳酸钠是重要的化工原料,其俗称是 [ ]

A.纯碱            

B.烧碱              

C.小苏打              

D.熟石灰

题型:计算题

那些地点需设置瓦斯检查点?

题型:计算题
Italian Lakes and Greek Islands (12 Days)
Your tour begins in Milan, Italy(意大利), and moves on to the pretty Italian Lake District and the attractive resort(胜地)of Stresa, your home for two nights. Collette Vacations has carefully chosen the Costa Victoria as your home for your 7—night journey along the waterways of the Mediterranean. The cruise ship is filled with the warmth and culture of Italy and is richly designed with entertainment(娱乐)areas and very good living conditions. It will take you to the places of your dreams.
You’ll spend 4 days touring Greek cities you’ve always heard about. In Katakolon, you will have an exciting tour to nearby Olympia without a guide. Then with a local guide you will visit the Greek islands of Santorini, which is often related to the story of the lost city of Atlantis, and Mykonos, a wonderful island with beautiful beaches.
Your journey ends in Verona, home of the love story Romeo and Juliet, with a fun—filled Goodbye dinner—a perfect ending to a pleasant journey.
12 Days, 25Meals: 10 Breakfasts, 6 Lunches, 9 Dinners
Day 1         Overnight flight to Italy
Days2—3       Regina Palace, Stresa, Italy
Days4—10     Costa Victoria ( Costa cruises)
Day 11        Hotel Leopardi, Verona, Italy
Day12        Leave for home
Please Note:
Leaving date
Price for one person
April 7
$2,099
June 2
$2,199
October 6
$2,099
November 3
$1,999
小题1:How is the journey planned?
A.It starts and ends in Italy.
B.It starts and ends in Greece.
C.It starts in Italy and ends in Greece.
D.It starts in Greece and ends in Italy.
小题2:What can be inferred from the travel plan?
A.The price may get lower than those in the plan.
B.The prices include three meals a day.
C.The price is the highest in summer.
D.The prices include entertainment service.
小题3:What does the underlined part “ the Costa Victoria” most probably refer to?
A.A famous hotel.B.A beautiful resort.
C.A comfortable ship.D.A long—distance bus.
小题4:Tourists will travel on their own in              .
A.StresaB.OlympiaC.MykonosD.Verona
题型:计算题

第6题的程序执行到DEL: JCXZ FILL指令时,CX寄存器的内容是______。

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