问题 选择题

关于做功和热传递,下列说法中正确的是(  )

A.做功只能把其他形式的能转化为热能[内能]

B.热传递过程实际上就是热能[内能]的转移过程

C.做功和热传递是没有区别的

D.做功和热传递对改变物体的热能[内能]而言效果总是不同的

答案

A、外界对物体做功,物体的内能增大,其它形式的能转化为内能;物体对外界做功,物体本身的内能减小,内能转化为机械能.故A错;

B、热从温度高的物体传给温度低的物体,或从物体的高温部分传到低温部分,叫热传递,实质是能量的转移,故B正确;

C、热传递过程是能量的转移过程,而做功过程是能量的转化过程,二者本质不同,故C错;

D、做功和热传递都可以改变物体的内能,二者本质不同,但在改变物体的内能上是等效的,故D错.

故选B.

选择题
阅读理解

Columbus College,241 Queen Elizabeth

Drive, Kowloon City

    Memo

To: All Staff

From: Jakie  Mok, Secretary; Sports Development Committee

Date: May 20,

    A week ago, "Sports for Life " programme was sent to the parents, requiring them to select a sport

they wanted their child to play. Since then, our staff have received lots of calls from parents asking for

more information about it. Here is a memo (备忘录) for your reference when you answer the phones.

Sports 1:Basketball

    We expect that this will be the most popular of the four sports. Therefore, students should be advised

to sign up as soon as possible. Students will take a private bus to and from Kwun Tong Sports Park. To

cover the cost of hiring a bus, each student will have to pay $10 each time. There will be four basketball

courts available for our use with one teacher watching over each game.

Sports 2:Gym

    We will be using St. Peter's Memorial Park. There are two reasons for choosing this park. First, it is

not very busy and crowded before 6:00 pm. Second, it has lots of trees with plenty of shade. Students

must bring along two bottles of water to prevent thirst. Three activities, skipping, jogging, outdoor

aerobics (有氧运动),all of which are free of charge, will be arranged. And there will be a teacher on

duty for each of the activities.

Sports 3:Hiking

     Hiking (远足) will take place at Kowloon Peak. The activity will start at 2:30 pm and finish 90 minutes

later. Three teachers will accompany the students, and a hiking instructor will accompany each group of

15 hikers. Each instructor will cost $75/hr. Students are advised to bring plenty of water and sunscreen.

Sports 4:Swimming

     The Kowloon City Aquatic Centre is a 10minute walk from our school. Four teachers will go to the

pool and conduct the goingson from the poolside. We will only be able to reserve the pool for one hour

(i.e.2:45 pm to 3:45 pm).Only students skilful at swimming can take up this activity. The pool will have

two lifeguards present. Girls must wear a swimming suit. The cost is $10 per visit.

1. Which of the following is TRUE according to the passage?

A. Students selecting basketball had better register early.

B. Students participating in gym should arrive at 6:00 pm.

C. Hiking usually begins at 2:30 pm and lasts 2 hours.

D. Students having swimming suits can take up swimming.

2. It can be inferred from the passage that ________.

A. students taking part in basketball will walk to the courts

B. every student can gain admission to one of the four sports

C. hiking students can have a regular rest in the shade of trees

D. students taking up the four sports should bring bottles of water

3. It can be concluded that ________.

A. each sport will take only one hour

B. students will be charged for the four sports

C. all the sports will take place at Kowloon Peak

D. teachers will accompany students on each sport

4. The purpose of the memo is to ________.

A. attract students' interest in the programme

B. require the parents to select a sport for their child

C. help the staff explain the programme to the parents

D. remind teachers and lifeguards to be present on time