如图所示,一质量为M的木板B静止在光滑的水平面上,其右端上表面紧靠(但不粘连)在

题型:问答题

问题:

如图所示,一质量为M的木板B静止在光滑的水平面上,其右端上表面紧靠(但不粘连)在固定斜面轨道的底端(斜面底端是一小段光滑的圆弧,其末端切线水平),轨道与水平面的夹角θ=37°,一质量为m的物块A从斜面上距离斜面底端8m处由静止释放,最后物块A刚好没有从木板B左端滑出,已知物块A与斜面间的动摩擦因数为0.25,与木板B上表面间的动摩擦因数为0.3,木板的长度L=8m,物块A可看作质点.sin37°=0.6,cos37°=0.8,g取10m/s2)求:

(1)物块A刚滑上木板B时的速度有多大?

(2)物块A与木板B的质量之比

m
M
为多少?

(3)物块A从开始下滑到相对木板B静止共经历了多长时间?

考点:匀变速直线运动规律的应用牛顿第二定律
题型:问答题

—LiYang is a hard-working boy.

—I agree. But he shouldn't _______ too late at night, or he'll be stressed out. [ ]

A. look up

B. stay up

C. make up

D. wake up

题型:问答题

患者,女,55岁,护士通过收集资料确认目前存在以下护理问题,应该首先解决的是()。

A.腹泻

B.语言沟通障碍

C.皮肤完整性受损

D.清理呼吸道无效

E.营养失调:低于机体需要量

题型:问答题

阅读下面短文并回答问题,然后将答案写在横线上(请注意问题后的词数要求)。

     What is the hottest topic at your school recently? In Hangzhou Yongjin Middle School, it's money.

     The school held an activity called "making money" last weekend. About 200 Junior 1 and Junior 2

students were divided into 30 teams. They went out ________________. What did they choose to sell?

Some sold newspapers;some chose bottled water;some sold environmentally friendly shopping bags

and bamboo baskets.

     Hu Qing's team decided to sell some useful books in front of the Children Activity Center. They thought parents would like to buy the books for their children. But unfortunately, they met urban management

officers. The officers asked them to leave. "We played hideandseek with the officers for the whole

morning, " said Hu. "Finally we had to give up."

     Wang Bing and her team sold ice cream in a square. They didn't meet any officers. But few people

were interested in what they were selling. The team then put up a board saying "For Country Kids". It

worked. More people came to their stall(小摊). A foreigner even gave them 100 yuan. "He didn' t want

any change. He said he wanted to help the children, " said Wang. "We were touched." Later that day they gave the 100 yuan and more to the "Project Hope" office.

     Meng Zhaoxiang and his team were luckier. They sold all their cakes in four hours, spending 39.5 yuan and getting back 80 yuan. They made 40.5 yuan. "It was not easy to make the money, " said Meng.

"Some people just looked. Others just tasted but didn't buy. Now I know how hard it is for our parents

to make money we need to lead happy lives. "

1. What is the main idea of the text?(no more than 10 words)

________________________________________________________________________

2. Fill in the blank in Paragraph 2 with proper words. (no more than 10 words)

________________________________________________________________________

3. What does the word "It" (Line 4, Paragraph 4) refer to? (no more than 20 words)

________________________________________________________________________

4. What is the writer's attitude towards the activity? (no more than 10 words)

________________________________________________________________________

5. What is the good of holding this activity?(no more than 10 words)

________________________________________________________________________

题型:问答题

对于淡漠型甲亢,下列哪项是错误的()

A.多见于老年人

B.病人乏力、明显消瘦

C.可仅表现为阵发性或持续性心房纤颤

D.不易发生甲状腺危象

E.眼征、甲状腺肿和高代谢症群均不明显

题型:问答题

国家和社会对残疾军人,因公致残人员以及其他为维护国家和人民利益致残的人员实行(),给予抚恤和优待。

A.特别保障

B.救助措施

C.特殊政策

更多题库