问题 选择题

如图是绵延在厦门环岛路上的“永不止步”群雕,将马拉松比赛的场景永远定格在这条世界上最美的赛道上,雕像大小与真人差不多,假设由密度为4×103kg/m3的合金雕刻而成,则每座雕像的质量约为(   )

A.5kg

B.50kg

C.200kg

D.2000kg

答案

答案:C

题目分析:大理石雕像的大小跟真人差不多,这一点提示了本题的解题方向:要估测雕像的质量,需将其与真人进行比较--雕像的大小跟真人差不多,即体积可以看成是相等的,而人的密度与水近似,密度为4×103kg/m3的,故可以根据m=ρV得出质量的大小.人的密度与水的密度差不多,大约是:ρ=1.0×103kg/m3

人的质量大约是:m=50kg

人的体积:

雕像的体积:V=V=50×10-3m3

雕像的质量:mV=4×103kg/m3×50×10-3m3=200kg

故选C.

点评:本题是根据人的质量和密度对这个雕像质量进行估测,需要学生知道人的密度和水的密度是差不多的.这对学生的要求比较高.要会估计人的质量和体积,是物理知识与实际的结合,体现了物理来源于生活的思想,属于中档题.

阅读理解

Earthquakes can be very scary(吓人的). But you need to keep your mind stable (坚定的) in order to make sure you are safe. Be calm and try not to run here and there.

If you manage to come out of your house, go to an open space like a garden or a park where you will be a lot safer. If you live quite some floors above in your building, try to find a place near a bulky(坚固的) object such as a bed. Curl up (蜷缩) and sit on the floor and make sure you are not near a window, fireplace, gas stove and so on. Remember don’t use lifts or escalators.

Some people say you should stand on a doorway. That is not true. If the doorway jambs (侧壁) are weak, they might fall on you. Also if people want to pass through that door, you may stop them. Leave all doorways free.

Another important thing to keep in mind is that you mustn’t climb down the stairs during an Earthquake. If the tremors (震动) stop, after a few seconds, just climb down the stairs as quickly as you can and move out of the building, but don’t run.

Earthquakes usually destroy gas pipes and electrical wires. Turn off the main gas. And don’t light candles or lighters and create an even bigger disaster.

If you’re driving and feel a shake, stop your car at the side of the road and get out. Make sure you are not on a bridge. Bridges and overhead roads (高架路) have the biggest danger of falling.

小题1: The best title for the passage should be       .

A.Dos and Don’ts Before an Earthquake.

B.What to Do in Case of Earthquake

C.Tips for Earthquake Preventions

D.Tips for Children in Earthquake.小题2:When an earthquake suddenly happens, you should       .

a. remain standing near a window             b. turn off the main gas

c. stay in an open space                     d. stand on a doorway

e. keep off  overhead roads

A.a, b, c

B.c, d, e

C.b, c, e

D.b, d, e小题3: Which of the following is NOT true, when an earthquake suddenly happens?

A.We can’t use the lift.

B.Curling up may be very dangerous.

C.We must turn off the gas.

D.We must get out of the car when the earthquake comes小题4: It can be learned from the passage that     .

A.keeping calm in time of earthquake is very important.

B.measures should be taken to make buildings stronger.

C.Knowledge of first aid must be used in an earthquake.

D.lots of things must be done to survive an earthquake.

名词解释

KP