问题 选择题

沿同一条直线运动的a、b两个质点,在 时间内的x—t图像如图所示。下列说法正确的是(   )

A.质点a作周期性往返运动。

B.在时刻, a、b的位移相同。

C.在时间内和时间内b发生的位移相同

D.在时间内,a通过的路程是b通过的路程的3倍,但位移相同。

答案

ABD

题目分析:从图像中可知,a的位移随时间做周期性变化,所以a做往返运动,A正确,

在时刻, a、b的位移相同,B正确,

时间内位移为-5m;时间内位移为5m,所以两个过程中位移大小相等,方向相反,C错误,

时间内,a通过的路程为30m,b通过的路程为10m,初末位置相同,所以位移相同,故D正确,

点评:图象类问题处理时要:先看轴,再看线,看看斜率,相相面.要明白各类图象的意义即可.

多项选择题
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Funeral homes aren’t just for dead peopled . They’re for our passed–on pets too these days. Pet Angel Memorial Center in Carmel. Indiana, helps guide grieving (悲痛的)animal owners through a vast range of burial and menorial options . The staff of five, all former clients (顾客), then carries out the owner’s wishes . Perhaps the most important service the center provides, though, is an understanding to cry on .

Owner Coleen Ellis started the country’s first pet funeral home there years ago after the death of her dog Mico. It was then that she discovered her veterinarian(兽医), like most throughout the United States, put dead animals in garbage bags and stored them in a freezer for up to one week . A disposal company then picked up the bodies and took them to a landfill(废物埋填地)site.

Before opening Pet Anget Memorial Center, Ellis worked in human funeral homes for 15 years, helping guide families through the end of life process. Her work with pets, though, is unusual. Only a handful of animal funeral homes exist, most of which Ellis said she helped get started.

Honoring dead pets and honoring people are similar in many ways. The 1,200 square –foot memorial center, located outside of Indianapolis, offer a full line of memorial items . The lowest priced package starts at $ 230  and includes pick-up , as well as a keepsake(纪念品)paw print. Friends, family and surviving pets often accompany grieving owners.

The atmosphere is different from a human funeral home, where people stay their distance to give the grieving family privacy. At the center , pet owners mourn together . Often times , if two visitations are going on, the families will share stores about their dead loved ones. It’s a very good healing experience.

63.What made Coleen Ellis have the idea of a pet funeral home?

A.Her dream to become famous in the USA

B.The cruel way of dealing with dead pet animal

C.Her determination to change her job

D.Her wish to make friends with pet owners

64.What do human funeral homes and animal funeral homes have in common ?

a. They both have a memorial center.

b. They both provide memorial items.

c. They have the same atmosphere.

d. In both places grieving people are kept company by their friends

A.a.b.c               B.a. c. d.                    C. b. c. d.           D.a.b.d.

65.The underlined word“visitations ”in the last paragraph refer to “     ”.

A.animal funerals                     B.places of funerals

C.pet owners                            D.sad stories

66.What is the passage mainly about ?

A.Coleen Ellis’ life                  B.Human funeral homes.

C.Veterinarians and animals      D.Animal funeral homes