组卷网 > 高中英语综合库 > 主题 > 人与自我 > 日常活动 > 日常生活
题型:阅读理解-阅读单选 难度:0.85 引用次数:75 题号:12607305

If you've ever pulled a rolling suitcase through the airport, chances are that you've also been annoyed by this common occurrence: the suitcase starts rocking back and forth on each wheel and finally tips over.

"It's a very classic phenomenon in physics," said Sylvain Courrech du Pont, a physicist at the University of Paris Diderot. "So if you disturb the system it goes very easily unstable. This is shared by many, many phenomena in nature."

Courrech du Pont and his students wanted to get to the bottom of why luggage tips. So they built what looks like the structure of a wheeled suitcase, and then filmed it rolling on a treadmill (a machine for running). Then they modeled what they saw mathematically.

And here's what they found. Under normal rolling conditions, the forward motion of the suitcase is perpendicular(垂直的) to the wheels' axis of rotation(旋转轴). All is good. But when you hit a bump or drag the handle fiercely and abruptly, one wheel lifts up. All of a sudden the pulling motion is no longer perpendicular to the still-rolling wheel's rotation axis, and the wheel corrects that by accelerating towards the center. But by that time the other wheel's coming down, the same thing happens, and now the suitcase is really rocking.

"And the first reaction you will have maybe is to slow down. But actually if you slow down you'll experience very big rocking. Therefore, the way back to a smooth ride is to keep up your speed," he says, "or move even faster, once rocking begins.

There are other solutions to suitcase instability—like doing a better packing job. "If you put heavy contents close to the axis of symmetry, then it will be stable, too."

And Courrech du Pont has one more piece of advice to avoid rocking in the first place: "If you go slow enough, it will always be stable." Keep that in mind, next time you're running to your gate.

1. What can we infer from the first two paragraphs?
A.Everyone has been upset by a rolling suitcase at the airport.
B.Physical phenomenon can be found in our daily life.
C.The disturbance of the system results from the instability of the suitcase.
D.The phenomenon of suitcase rolling is rare at the airport.
2. What mainly causes the suitcase rocking?
A.It hits a bump
B.One wheel lifts up.
C.One wheel falls down.
D.It is not perpendicular to the axis.
3. How do people react to a rocking suitcase firstly?
A.tip it over
B.accelerate its moving.
C.slow down its moving
D.drag its handle with great strength.
4. How many ways are mentioned to keep the suitcase stable in the text?
A.oneB.two
C.threeD.four

相似题推荐

阅读理解-阅读单选(约260词) | 较易 (0.85)
名校

【推荐1】Choosing a vacation place your kids would love is quite a headache. Here are some highly preferred fun vacation places for you, which would make sure your entire family has fun together.

Hersheypark

Hersheypark, the "Chocolate Town" of USA, in Hershey, Pennsylvania, is now a main theme park with sixty rides. The amazing water rides, family rides, live concerts and shows make Hersheypark a perfect place for the young children. It also has a water park known as the "The boardwalk at Hersheypark" and a zoo.

Old Orchard Beach in Saco, Maine

The Old Orchard beach, where there is the amazing sand, water, rides, some fried food, and great fun games, can keep your kids busy and happy. Besides, there are downtown shops with great beach food.

Snowbird Resort in Snowbird, Utah

As a great place for those who enjoy the snow, Snowbird resort allows families to enjoy many activities in the winter months, such as snowboarding and ice skating. The live music concerts are held year round.

Hilton Waikoloa Village in Waikoloa, Hawaii

This is actually a fun vacation place when you are looking out for a getaway with your kids. Hilton Waikoloa Village is the place to go if you would like to have your children enter for Camp Menehune. Looking for the chance to feed birds is an exciting experience. However, an activity that your kids would enjoy most is the communication with dolphins.

1. What can visitors do in the Snowbird Resort?
A.Visit a water park.B.Enjoy ice skating with their families.
C.See many lovely dolphins.D.Taste great beach food.
2. Where can visitors go if they want to have their children attend Camp Menehune?
A.Hersheypark.B.Old Orchard Beach.
C.Hilton Waikoloa Village.D.Snowbird Resort.
3. What is the author’s purpose in writing the text?
A.To introduce several fun vacation places for families.
B.To tell about the traditional relaxing holidays.
C.To advertise the best vacation places in winter.
D.To show some theme parks in the world.
2018-03-18更新 | 80次组卷
阅读理解-阅读单选(约380词) | 较易 (0.85)
名校

【推荐2】I was reading these interesting stories behind a group of great logos (标识) in the world. Personally Nike is my favorite one - it's so simple. And I liked the stories behind them, which made me forget all other things. McDonald's, Apple, Mercedes Benz and Adidas own great logos as well, and they are among my favorites.


Nike

In the Greek myth, Nike is the goddess of victory and the source of inspiration for soldiers. This logo represents the wing in the famous statue of the Greek goddess. Nike's logo was designed by Carolyn Davidson in 1971 for $ 35, and was registered as a trademark in 1995.


McDonald's

The logo was designed in 1962 by Jim Schindler to resemble the arch-shaped (拱形的) signs on the side of the company's then walk-up hamburger stand. Later on, the two golden arches were combined together to form the M. The McDonald's name was added to the logo in 1968.


Apple

There are different stories behind Apple's logo. The first logo was a reference to the religious story of Adam and Eve, in which the apple represented the fruit of the Tree of Knowledge. One year later, the second logo was designed in 1977 by Steve Jobs and Ronald Wayne, and it described Sir Isaac Newton sitting under an apple tree. This logo didn't stay long. One year later it was replaced almost immediately by graphic designer Rob Janoff's“rainbow apple", a rainbow-colored silhouette (轮廓) of an apple with a bite taken out of it. And then the rainbow-colored apple was replaced by the one-colored logo in 1998. It has not been changed so far.


Mercedes Benz

The Mercedes Benz logo, which was originally created by Gottlieb Daimler in 1909, consists of a simple description of a three-pointed star that represents its rule of the land, the sea and the air. The company was founded by Gottlieb Daimler and Wilhelm Maybach. Mercedes is the name of Maybach's elder daughter, while Benz came as a result of a combination with Benz, Cie and DMG in 1926.


Adidas

The Adidas logo, which was created by the founder of the company Adi Dassler, represents mountains, pointing towards the challenges that are seen ahead and goals that can be achieved. The logo was used for the first time in 1967.

1. What does the author think of the stories of the great logos?
A.They are boring.B.They are forgettable.
C.They are attractive.D.They are practical.
2. What does Nike's logo stand for?
A.The goddess of victory.B.The source of inspiration for soldiers.
C.The statue of the Greek goddess.D.The wing of the Greek goddess.
3. We can learn that Apple's present logo is ________.
A.the religious story of Adam and EveB.a bitten apple with only one color
C.Newton's sitting under an apple treeD.the rainbow-colored bitten apple
2021-08-16更新 | 99次组卷
阅读理解-阅读单选(约370词) | 较易 (0.85)
文章大意:本文是一篇应用文。文章介绍的是四种不同类型的省钱应用程序。

【推荐3】There are different types of money-saving apps, and all of them work in different ways. Here are 4 of the best apps that can help you save much money.


Capital One Shopping

     Capital One Shopping can compare prices automatically as you shop CapifalOne online. As you add items Shopping to your cart at an online retailer, this app will search the web for better deals and coupon codes. You can follow the links to other retailers offering a better price and use the available codes to save. You can even use this app while shopping at brick-and-mortar (实体的) stores.
Paribus

There’s nothing more upsetting than buying PARIBUS something and then seeing it for sale at a lower price a few days later. Wouldn’t it be nice to get that money back? Now you can. Paribus helps you get money back by tracking your purchases from major stores and negotiating refunds. It also helps you get compensated (补偿) for late deliveries and makes sure you don’t leave it too late to return anything you bought.


Qapital

By setting goals and rules, Qapital helps you to make the most of your money and to save wisely. There’s a Payday Divvy feature that divides up your commitments between spending and saving. You’ll also be able to take part in “Money Missions”, which are fun challenges designed to give you insight into smart financial investments. If you want to invest too, you can use Qapital’s pre-built portfolios, which are tailor-made (特制的) to the timeline and amount you input.


Digit

If you can’t figure out how much you can afford to save, Digit will analyze your spending habits and allocate (分配) I a certain amount to your savings. If the app knows you have spare money to save, then it will be moved automatically, and if you don’t, it will stop, so there’s no risk of being left with no cash for the basics. You can sign up for a free trial for a month, and after that, the monthly price is $5.

1. Which of the following best describes Capital One Shopping’s function?
A.Recommending brick-and-mortar stores.B.Encouraging retailers to give coupon codes.
C.Finding better deals for consumers.D.Comparing the quality of different products.
2. Which app are people most likely to choose when they want to learn about investing?
A.Capital One Shopping.B.Paribus.C.Digit.D.Qapital.
3. What is the purpose of this text?
A.To compare four new apps.B.To recommend some money-saving apps.
C.To encourage people to save money.D.To advertise some apps created by the author.
2023-10-13更新 | 54次组卷
共计 平均难度:一般