问题 实验题

研究的物理量不易直接测量时,都需要想办法把它们的大小间接表示出来。例如:如图所示.甲实验是让木块在木板上做        运动,通过弹簧测力计的示数间接显示滑动摩擦力的大小;乙实验中钢球的动能大小是通过               间接反映出来的.

答案

匀速直线、 木块移动的距离

题目分析:甲实验中,因为当木块在木板上做匀速直线运动时,测力计的拉力与摩擦力是一对平衡力,由此可知:由测力计的示数间接显示滑动摩擦力的大小的条件是,一定让木块在木板上做匀速运动.

乙实验中,球的动能大小是通过球对木块做的功,即木块移动的距离来体现动能大小的,所以要比较木块移动的距离来间接反映.

点评:题考查的两个实验都采取了转换法来设计的,这要注意间接反映时实验所具备的条件.

填空题
阅读理解

阅读理解。

     People in China are among the  most fearful of getting old, a new global survey suggests.

     According to Bupa, a British healthcare organization, which asked 12262 people in 12

countries about their attitudes toward aging, 28  percent of the Chinese polled said they feel

depressed when they think about getting old.

     And although 72 percent of all respondents aged 65 and over  said they do not feel old,

the survey conducted in June and July this year found more than half of those aged 45 to 54

in China already consider themselves to be elderly. About 30 percent  of Chinese respondents

said they worry about who will look after them in later years, while 91 percent agreed the

government of the world's most populous nation  should improve care for the elderly.

     However, because people in China think about their future earlier, research suggests the

country could be one of the best prepared for addressing the aging problem. About one third

of Chinese respondents--more than double the global average-said they have put money aside

for retirement, while 46 percent have taken out insurance, the poll showed. Despite being one

of the best prepared nations, three fifths of those surveyed in China expect their family to care

for them when they can no longer do so themselves.

     A Bupa-sponsored report,however, revealed that the "informal care network"  (the traditional

pattern of families looking after the elderly) is disintegrating. This is due to a number of factors,

said the report, including structural changes to the population, the increase of women in employment,

the increase of one-person households and the rise in divorce rates.

     The first batch of Chinese couples with only one child are largely in their 50s or 60s because the

country's family planning policy was adopted in the late 1970s.

     Li Yinping, 55, a retired accountant, said she thinks only people in their 70s can be called old.

She said her pension is enough to support her in later years and that her only hope is that her son

can visit regularly. "I don't worry about my later years at all," said Li. "When I'm old, I can turn to a

rest home. The local hospital can deliver the medicine I need with just a phone call."

     Xiao Zhe, a 26-year-old computer engineer in Beijing, is an only child whose parents live in his

hometown of Chongqing. "I'm so busy with my work that I can't go back to visit them often," he said.

"When they're not able to care for themselves, I will hire a nurse to look after them."

     China will become the oldest society in the world by 2030, according to a recent report by a

Beijing-based government think tank. The United Nations also forecasts that people aged 60 and

over will account for 28 percent of the country's total population by 2040.

1. Which of the following can be best title of the passage? ________.

A. the Aging problem of China    

B. Who is to look after the elders

C. Chinese are afraid of getting old

D. Old Home Is Popular in China

2. Many factors EXCEPT _______ have a great impact on informal care network.

A. structural changes to the population

B. the increase of women in employment

C. the development of economy

D. the rise in divorce rates

3. According to the passage, most Chinese people are ________ to guarantee the late life. 

A. putting away some money

B. giving birth to more children

C. hiring a nurse

D. turning to a rest home

4. What can be inferred from the last four paragraphs? ________ 

A. Chinese government put forward family planning policy in the late 1970s.

B. Senior citizens will account for a high percentage of the country's total population by 2040.

C. The local hospital can deliver the medicine to senior citizens in need.

D. There is a trend that grown-up children live apart from parents