问题 计算题

如图所示,从某高处以6 m/s的初速度、30°抛射角斜向上方抛出一石子,落地时石子的速度方向和水平线的夹角为60°,求石子在空中运动的时间和抛出点离地面的高度。(g=10 m/s2)

答案

解:如图所示,石子落地时的速度方向和水平线的夹角为60°,则

取向上为正方向,落地时竖直速度向下,则-vy=v0sin30°-gt,得t=1.2 s

由竖直方向位移公式:5×1.22 m=-3.6 m,负号表示落地点比抛出点低

填空题
阅读理解

Employees are being flooded with too much information that has little to do with their work, according to a new survey.

On average, white-collar workers spend 51 percent of their work time receiving and processing information. Only one third of it was relevant to their work, the survey found. Information overload for white collar workers has become a global issue. The huge amount of information has already affected their efficiency in management as well as their performance at work.

Buried with e-mails

Every morning, a secretary at the human resources department of an auto parts company opens her e-mail box, only to find it crammed with at least 50 unread mails. For her, even scanning through these e-mails every day takes at least half an hour. Some of her colleagues are not so lucky — they have to read at least 100.

Bothered with calls

Telephone calls are also causing a problem. More than 40 percent white-collar workers chose mobile phones as the preferred way to communicate important and urgent business matters.

Talking saves time and energy over the clicking, reading and replying to e-mails, but phone calls are also more distracting(分心的). While answering a call, a clerk is likely to put away a much more important task at hand and start the business being talked about on the phone.

Solution? Not yet.

Many companies start with providing staff with better computers, better Internet access and more advanced gadgets(装置). For example, staff members above a certain level in one company will be provided with a blackberry phone for easier access to their e-mails. The company has also organized many lectures on efficient ways of e-mail management. Yet most white-collar workers think their companies can do more.

小题1:What does the new survey find about white-collar workers?

A.They spend 51% of their work time on meetings.

B.Only half of the information they receive is useful.

C.Over 60% of them prefer to use the telephone.

D.Some of them have to read at least 100 e-mails every day.小题2:Telephone calls cause a problem because ________.

A.they take up the time to receive and send e-mails

B.they are often not answered

C.they are mostly not about business

D.they may lead to the changing of work schedule小题3:How do some companies try to solve the problem of information overload?

A.They start to give staff a pay rise.

B.They plan to employ more people.

C.They provide employees with more advanced equipment.

D.They organize lectures on how to reduce stress.小题4:What is the major issue discussed in this text?

A.Poor management leads to inefficiency at work.

B.Junk mail is causing big trouble.

C.White-collar workers suffer from information overload.

D.Better computers are in need in workplaces.