试题与答案

一列简谐横波沿x轴传播,相距2.0m的两个质元的振动图象分别为图示中的实线和虚线

题型:选择题

题目:

一列简谐横波沿x轴传播,相距2.0m的两个质元的振动图象分别为图示中的实线和虚线,已知该波的波长m,则以下说法正确的是

A.该波上质元振动的振幅为2.0cm

B.该波上质元振动的周期为0.25s

C.该波的波速可能为m/s

D.该波的波长一定为8.0m

答案:

AC

由振动图像可知该波上质元振动的振幅为2.0cm,故A正确

该波上质元振动的周期为4s,故B错误

若波向右传播,则,则,因为m,所以可得波长,则波速,若波向左传播,则,则,因为m,所以可得波长,则波速,则C正确D错误

故选AC

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题型:阅读理解

Today, as with so many days, I found myself stuck in a traffic jam, and I thought I’d share my little trick for keeping calm when it seems like you are creeping along(缓慢行进).

The key to understand is that traffic jams don’t take as long as they seem to. It’s just that when we are in a hurry, and think we should be moving, but time appears to pass more than it does. To really show this, the next time you are stopped at a light that always seems to take forever to change, try to do something with your phone, your laptop, whatever you have available, and watch how much briefer the light seems.

When you enter a jam on the highway, reset your trip plan and care the time. Then, when you clear the jam, and are normally on your way again, care the distance of the jam, and the time it took to get through it. For my experience today, it took me 6 minutes to go 2 miles. Now, it happens to be mathematically convenient that your average speed on the highway is about 60 mph, or a mile per minute. So to estimate what time the jam actually cost you, just take your traffic jam passing time, and subtract(减去) the distance covered, which we know is a good estimate of the time it would have taken with no traffic jam. In my case, all that added up to 6-2="4" minutes.

Do this for every jam you are subjected to every time and watch how much less stressful they become once you understand how little time you are really losing.

小题1:We can infer from Paragraph 1 and 2 that ________.

A. there was no traffic jam in the past

B. modern people are under great pressure

  time passes much faster during traffic jams

D. people in traffic jams are usually impatient

小题2:What does the writer suggest when caught in traffic jams?

A. Playing a trick on other drivers.

B. Figuring out how much time the jam actually cost you.

  Doing some math problems.

D. Informing the boss about the delay.

小题3:The underlined phrase “subjected to” in the last paragraph probably means ________.

A. experience          B. avoid                admit                     D. control

小题4: What’s the main idea of the passage?

A. Math is closely connected with life.

B. Stress is always a bad thing.

  Traffic jam is not as bad as you think.

D. There is no use complaining about traffic jams.

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