问题 问答题

小华想从水槽中取一些水,质量刚好是20g,但手头没有天平.正在冥思苦想的时候,老师提醒他,利用实验桌上的量筒就可以做到.小华不明白:“量筒是测体积的,我要的是准确质量的水”.老师点拨到:“其实这只是一个间接测量问题,只要计算一下就解决”.

(1)你知道怎样用量筒量取一些水,确保质量刚好是20g吗?请计算并简要说明(不要写实验步骤).

(2)20g水的重力为多少N?

答案

(1)由题目给出的条件m=20g和水的密度可计算出水的体积,

由ρ=

m
V
得V=
m
ρ
=
20g
1g/cm3
=20cm3=20ml,

所以不用天平,只用量筒量量出20ml的水就是20g酒精.

(2)m=20g=0.02kg,

G=mg=0.02kg×9.8N/kg=0.196N.

答:20g水的重力为0.196N.

阅读理解

The 18-meter-tall Rubber Duck arrived in Beijing on Friday. It was placed on waters in the International Garden Expo Park, where the Yongding River passes through.

The Rubber Duck exhibition was designed by Dutch artist, Florentijn Hofman. It was part of the activities of Beijing Design Week, which ran from September 26 to October 3 in 2013.

The Rubber Duck stayed in the park until September 23, then moved to the Summer Palace, a famous Beijing tourist spot, where it was on display until October 26.

The duck is made of over 200 pieces of rubber. It was guarded not only by staff, but also by 10 volunteers wearing yellow T-shirts and hats with a rubber duck logo.

Sun Yidong, a volunteer who guided visitors to the duck, said the art brought energy to the traditional Chinese park.

“Seeing the giant Rubber Duck makes me feel like I’m a kid again.” Sun said.

Because of the rain on Friday, there were not too many people coming to see it. The Expo workers said they expected more people to come and visit the duck on weekends.

Zhao Yan said she had been following news about the duck since 2007, when the duck began its journey.

“I even considered going to Hong Kong to see it. It’s great that the duck is in Beijing,” Zhao said.

Before arriving in Beijing, the Rubber Duck traveled to 13 cities in nine countries. “The aim of the Rubber Duck is simply to bring everyone back to their childhood again,” said Zeng Hui, a leader of the Beijing Design Week Organizing Committee Office. “It can be a toy for adults.”

根据材料内容选择最佳答案,并将其标号填涂在答题卡的相应位置。

小题1:The Rubber Duck went to _______ after it left the International Garden Expo Park.

A.the Olympic Park

B.the Summer Palace

C.Beihai Park

D.Zhong Shan Park小题2:The Rubber Duck arrived in Beijing on _______.

A.Thursday

B.Friday

C.Saturday

D.Sunday小题3:Why weren’t there too many people going to see the Rubber Duck on Friday?

A.They were not interested in it.

B.They didn’t have enough time to go there.

C.The weather was not good.

D.The tickets were expensive.小题4:Which of the following is NOT true?

A.The Rubber Duck started its journey in 2007.

B.Before arriving in Beijing the Rubber Duck was shown in 13 cities.

C.The Rubber Duck is made of more than 200 pieces of rubber.

D.A German artist designed The Rubber Duck.小题5:What can we learn from the passage?

A.The Rubber Duck can remind people of their childhood.

B.Beijing Design Week finished on October 2.

C.Sun Yidong was a visitor.

D.Volunteers wore white T-shirts.

多项选择题