问题 计算题

我国自行生产的混合动力汽车已经服务于生活。混合动力汽车启动时,内燃机并不工作,蓄电池通过某种方式向车轮输送能量;当需要高速行驶或蓄电池储存电能过低时,内燃机启动,既可以向车轮输送能量,也可以同时给蓄电池充电;当车辆需要全力加速时,内燃机和蓄电池还可以同时向车轮输送能量。

(1)根据以上描述,请你说出一种混合动力汽车不同于普通汽车的优点____________ 。

(2)下表是某台混合动力汽车所用的镍氢蓄电池组的部分参数(其中容量即为电荷量),试求该蓄电池组最多可储存多少电能。

(3)测试人员驾驶该车在平直公路上匀速直线行驶0.5h,观察仪表盘,发现这段时间内汽车内燃机消耗燃油 4.475kg,车速为50km/h,蓄电池组储存的电能由最大值的60%增加到80%。从汽车使用技术手册中,测试人员发现该车使用的燃油的热值为4.0×107J/kg,汽车行驶时所受阻力f和车速v的关系如下图所示。

①内燃机若完全燃烧燃油4.475kg能放出多少热量?

②车速为50km/h时汽车发动机的动力有多大?

③试计算该汽车内燃机的效率(不计内燃机外机械传动及充电过程中的能量损失)。

答案

(1)清洁、污染少;能源利用率高等。

(2)W=1.08×108J

(3)

①Q=1.79×108J

②F=f=2000N

③行驶过程中充入的电能W1=W×(80%-60%)=2.16×107J,行驶机械功W2=F×S=2000N×25000m=5×107J,内燃机的效率η=(W1+W2)/Q=40%。

阅读理解

Are you still doing the V for victory sign? It’s out. The latest popular hand gesture(手势)is to curl both of your hands and put them together to make a heart—shape. Known as “hand heart”, many young stars in the US including Justin Bieber , Blake Lively and Taylor Swift have done the move in recent photos.

“The heart — hand gesture means something between ‘I love you’ and ‘thank you’, ”said the country singer Taylor Swift,21.”It’s a sweet, simple message which you can send without saying a word.”

Taylor Swift often puts her hands above her head in the heart shape at her concerts. And she is believed to be the first to make the gesture popular.

Last month during a charity show, Justin Bieber and his superstar friends did it to help out three kids whose parents were killed in a car accident. The gesture became a real hit after that.

“It used to take longer for nonverbal(不用语言的)culture to move. But now ,with smart phones and the Internet, it’s much faster,” said Patti Wood, an American language expert.

In the Republic of Korea, the hand heart has been popular for a long time, in a different way. People there like making a “bigger heart” by putting their hands above their heads and making a heart shape with their arms. It means: “I love you.”

小题1:When we want to express ideas, we often move our hands to mean something besides language. Do you know the meaning of this gesture(手势)?

A.Good luck.

B.We’ve won.

C.Everything is all right.

D.Best wishes.小题2:Who is the first to make the heart — hand gesture popular?

A.Justin Bieber

B.Blake Lively

C.Patti Wood

D.Taylor Swift小题3:A charity show is a show that is put on to.

A.help the people in need

B.make a gesture popular

C.express your love or thanks

D.show your special gesture小题4:Which of the following statements is true?

A.Smart phones and the Internet are improving fast.

B.Smart phones and the Internet used to take longer time in use.

C.It’s much easier for nonverbal culture to reach more people.

D.It takes nonverbal culture a long time to become popular.

单项选择题