以下运动中在相等的时间内速度变化不相同的是( ) A.自由落体运动 B.竖直上抛

题型:选择题

问题:

以下运动中在相等的时间内速度变化不相同的是(  )

A.自由落体运动

B.竖直上抛运动

C.匀速圆周运动

D.平抛运动

考点:加速度自由落体运动平抛运动匀速圆周运动
题型:选择题

某商场宣传在“五一黄金周”期间对顾客购物实行一定的优惠,商场规定:

①如一次性购物不超过200元,不予以折扣;

②如一次性购物超过200元但不超过500元的,按标价给予九折优惠;

③如一次性购物超过500元的,其中500元给予9折优惠,超过500元的部分给予八五折优惠.某人两次去购物,分别付款176元和432元,如果他只去一次购买同样的商品,则应付款(    )

A.608元

B.574.1元

C.582.6元

D.456.8元

题型:选择题
在○里填上“>”“<”“=”。
1.5时○1时50分400分○5元
890千克○1吨2100毫升○2.1 升
9立方米○900立方分米
题型:选择题

二维图像上增加彩色多普勒血流显示,则帧频会

A.增高

B.降低

C.不变

D.增高2倍

E.降低2倍

题型:选择题

阅读理解

       Ralph and Norton can grow to be 40 feet long and live in a tank as large as a football field.What are they?They're the only two whale sharks at a North American aquarium (水族馆).

       You can see Ralph and Norton at the world's largest aquarium,the new Georgia Aquarium in Atlanta.

The aquarium's giant tanks hold eight million gallons of water and will be home to about 100,000 fish!

       The aquarium was designed to look like a giant ship breaking through the waves.It has 60 different habitats from the sea and five galleries (展馆),each with a different theme.About 2.4 million visitors are expected to come each year."We want to be the world's most engaging aquarium." said Jeff Swanagan,the aquarium's executive director.

       Ralph and Norton arrived in June,2005 from Taiwan.They were only 15 and 13 feet long,but they may grow to be more than 40 feet long!Whale sharks are the world's largest fish.Three fulltime vets will work there to make sure that Ralph,Norton,and all of the aquarium's sea life stay healthy.Students from the University of Georgia will help run the aquarium and conduct research at the animal hospital.

       The aquarium was paid for almost completely by a $200 million gift from Berne Marcus,cofounder of the Home Depot Inc,and his wife,Billi."It's going to be the most unique aquarium in the world,"said Marcus.Marcus said the aquarium was a "thank you" note to the city of Atlanta and the State of Georgia,where the Home Depot first opened for business.

1.According to this passage,Ralph and Norton are________.

A.polar bears  

B.whale sharks

C.penguins

D.dolphins

2.The world's largest aquarium located in________.

A.Los Angeles  

B.New York

C.Atlanta

D.Miami

3.Which of the following is TRUE?

A.The aquarium was designed to look like a giant shark.

B.The aquarium's giant tanks can hold eighteen million gallons of water.

C.Ralph and Norton arrived in June,2005 from Japan.

D.Marcus helped to build the aquarium to show his thanks to Atlanta.

题型:选择题

质量为m的物体静止在粗糙的水平面上,当此物体受水平力F作用运动距离S时,动能为Ek1,而当此物体受水平力2F作用相同的距离时,其动能为Ek2,则(  )

A.Ek2=Ek1

B.Ek2=2Ek1

C.Ek2>2Ek1

D.Ek1<Ek2<2Ek1

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