验证机械能守恒定律实验中,已知打点计时器所用电源的频率为50赫兹(HZ),即相邻

题型:实验题

问题:

验证机械能守恒定律实验中,已知打点计时器所用电源的频率为50赫兹(HZ),即相邻两个点之间的时间间隔为0.02s 。查得当地重力加速度g=9.8m/s2,测得所用的重物的质量为1.00千克。实验中得到一条点迹清晰的纸带,如图所示,把第一个点记作0(初速度为零) ,另选连续的4个点,A、 B 、C、 D作为测量的点。经测量知道A、 B 、C、 D各点到0点的距离分别为62.99cm,70.18cm,77.76cm,85.73cm。根据以上数据可知道,重物由0点运动到C点过程中,重力势能减少量等于______________(J) ,在此过程中动能增加量等于______________(J)(结果保留三位有效数字)。

考点:实验:验证机械能守恒定律
题型:实验题

脊柱骨折病人急救运送方法,下列哪种是正确的()。

A.用软担架搬运

B.三人平托放于硬板上搬运

C.二人抱持搬运

D.一人抱持搬运

E.一人背负搬运

题型:实验题

一笔8000元的借款,约定按10%的单利率计息,则4年到期时一并归还本利和应为( )。

A.11713元

B.11200元

C.10400元

D.8320元

题型:实验题

ふるさとの母から届いた手紙を(    )うちに、思わず涙がこぼれた。

A.読んでおく

B.読んでいる

C.読んである

D.読んでしまう

题型:实验题

The average age for women to marry is between 18 and 25.25 tend to (1) when somewhat older. A church wedding often (2) the legal civil ceremony, and a large reception, which often involves (3) music and dancing, is held in the evening. Wedding traditions include (4) money on the bride’s dress to represent future prosperity, the groom (5) the bride at her home, and the couple pulling on opposite (6) of a loaf of bread—whoever gets the largest piece will be (7) boss of the family. Honeymoons are a new tradition.
The principle (8) mutual support is valued in the Bulgarian family. The elderly are (9) cared for by their adult children. Unmarried adults live with their (10) and many newly married couples live with one set of parents (11) they are able to get housing of their own. Most families (12) urban areas live in apartments, which are in short
supply, while (13) in rural areas usually have their own houses. Many village houses (14) owned by families who live in urban areas, who use them_ (15) summer and weekend retreats, or for retired parents.
Most families in (16) areas do not have more than two children, while families in (17) areas tend to be larger. Grandparents play an important role in (18) care, particularly in urban areas, where most women work outside the (19) . Men of the younger generation have begun to help with household (20) , once considered only women’s responsibility.

题型:实验题

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