问题 选择题

关于冲量,以下说法错误的是(  )

A.只要物体受到力的作用,物体受到的总冲量就一定不为零

B.只要物体受到的合外力不为零,物体在任一△t时间内所受的总冲量就一定不为零

C.如果力是恒力,则冲量的方向就是该力的方向

D.做曲线运动的物体,在任何△t时间内所受的总冲量一定不为零

答案

A、物体受到力的作用,如果合力为零,则物体受到的总冲量为零,故A错误;

B、冲量等于力与时间的乘积,只要物体受到的合外力不为零,物体在任一△t时间内所受的总冲量就一定不为零,故B正确;

C、如果力是恒力,力的方向不变,冲量的方向不变,冲量的方向就是该力的方向,故C正确;

D、做曲线运动的物体所受合力不为零,在任何△t时间内所受的总冲量一定不为零,故D正确;

本题选错误的,故选:A.

单项选择题
阅读理解

Dave Bruno works as an online marketing manager. Several years ago, one weekend Bruno and his family did a major house cleanup and then donated several bags of unneeded items to the local Goodwill store. “After all were done, I looked around and realized that I still had too much stuff”, says Bruno, “It occurred to me that maybe I wanted to lead a simple life but in reality I behaved differently.” That realization prompted the 39-year-old father of three to try an experiment, “The 100Thing Challenge”.

With the goal of breaking free of what he calls a “bad habit of consumerism(消费主义), Bruno was determined to live for one year with just 100 personal items. He cut down his possessions to 94 items, including a Bible, laptop, guitar, wedding ring, car and clothes. He created some guidelines for the experiment since his wife and daughters did not participate, familyshared and household items did not count as personal items. He also grouped together some basic things such as underwear and socks. Bruno began blogging about his new lifestyle and eventually wrote a book, The 100 Thing Challenge: How I Got Rid of Almost Everything, Remade My Life, and Regained My Soul.

Since completing the experiment, Bruno has continued to live by the motto: reduce, refuse, and rearrange and maintains just 110 personal things. “ Nearly three years of living with a minimal amount of personal possessions, I’m no longer in the habit of consuming for the sake of consumption (消费),” he wrote in his blog last week, “That has freed me up for all sorts of better endeavors (活动) than shopping—like spending time with family and writing a book and planning for business opportunities.”

Bruno’s project has also inspired others to live minimally, many of whom post their own 100 Thing Challenge updates on YouTube. “The reality is that the 100 Thing Challenge is surprisinglyeasy”, says Bruno, “I’m  not saying there were no challenges or disappointments. I miss some things, but not that much. Frankly, it’s far easier to live with less stuff than with excessive trash.”

小题1:What does the underlined sentence mean in Paragraph 1?

A.Bruno regretted to have an easy life.

B.Bruno had a special behavior in reality,

C.Bruno and his family led a happy life.

D.Bruno would have liked a life with fewer items.小题2:The things were included in Bruno’s 94 items EXCEPT____________.

A.socks

B.a Bible

C.cookers

D.a wedding ring小题3:What is the best title for the passage?

A.Live with 100 Things

B.Defeat 100 Challenges in Life

C.Survive by Your Motto

D.Consume for Consumption’s Sake