问题 填空题

现代家庭厨房里蕴藏着大量的物理知识:

(1)水沸腾时可以发现壶嘴喷出大量“白气”,这是水蒸气 ______形成的,仔细观察,会发现最靠近壶嘴的地方却不会出现“白气”,这是因为 ______的缘故;

(2)电饭锅是利用电流的 ______效应制成的;

(3)开启醋瓶的盖子后,弥漫着“醋”香,这是由于 ______;

(4)筷子实质上是一种 ______杠杆(填“省力”、“费力”或“等臂”);

(5)从厨房中你还能发现哪些物理知识?试举一例(要求写出厨房器具或现象及其所涉及的物理知识):______.

答案

(1)“白气”是水蒸气遇冷液化形成的小水滴;水蒸气遇冷以后才能液化成小水滴,在靠近壶嘴地方看不见“白气”,说明靠近壶嘴的地方温度高;

(2)电流通过导体时会将电能转化为热,这种现象叫电流的热效应,电饭锅就是利用电流的热效应来工作的;

(3)闻到了“醋”香,是因为“醋”分子运动到了鼻子中,引起了嗅觉,说明分子不停地做无规则的运动;

(4)使用筷子时,动力臂是小于阻力臂的,所以筷子属于费力杠杆;

(5)厨房做菜时要用刀,有时我们要把刀磨一磨,这是为了减小受力面积,从而增大压强.

故答案为:(1)液化,靠近壶嘴的温度高;(2)热;(3)分子不停地做无规则的运动;

(4)费力;(5)菜刀,减小受力面积可增大压强.

阅读理解

阅读理解。

                                                                         News

     1) Shanghai-China's biggest city received 279,700 overseas visitors in the first quarter of the year, a 10.6

percent over last year.

      2) At 00:00 on May 8th, 1996 (Beijing time), Beijing's telephone number will be changed from seven digits

to eight digits. How to change: Add 6 in front of the old seven digits telephone numbers.

     3) Eight persons were killed and 15 badly hurt at a traffic accident in Rongxian of Sichuan on April 16th.

Sichuan Daily reported last week. The bus carrying 23 people was running from Rongxian to Shuanggu on the

morning of April 16th, when the bus failed to pass a sharp turn and fell into a field located 41 meters below the

road.

1. The traffic accident happened _______.

A. long before

B. as we expected

C. in Shanghai

D. when those people were on their way to Shuanggu

2. Li Lei's aunt lives in Beijing. Her telephone number was 6972478 before 1996. Now her

     telephone number must be ______.

A. 69724786

B. 29179966

C. 66972478

D. 69672478

3. ______, 279,700 people visited Shanghai.

A. Last week

B. From April to May

C. In the first four months of the year

D. During the first three months of the year

4. At the traffic accident, ______.

A. eight people were dead

B. twenty-three people were dead

C. thirty-one people were badly hurt

D. eight persons were badly hurt

5. The bus fell into a field. It's______ from the road to the field.

A. 16 meters long

B. 41 meters wide

C. 16 meters high

D. 41 meters deep

选择题