问题 计算题

(13分)一火车以2 m/s的初速度,0. 2m/s2的加速度向东做匀加速直线运动,

求:(1)火车在第3 s末的速度

(2)前4 s内的位移

(3)第4 s内的位移和平均速度

答案

(1)2.6(2)9.6m(3)2.7

题目分析:(1)根据题意,以东为正,由

,则火车第3s末的速度为向东的2.6

(2)根据公式:

(3)第4s内的平均速度为第3.5s时的瞬时速度则可得

则由

第4s内的位移为向东的2.7m和平均速度为向东的2.7

点评:本题难度较小,其中需要注意的是计算速度、位移时要注意规定正方向,利用匀变速直线运动规律,带入公式及可求解,考查了学生对公式的记忆能力

填空题
阅读理解

Napoleon agreed to plans for a tunnel (隧道) under the English Channel in 1802. The British began digging one in 1880. Neither tunnel was completed. Europe has had to wait until the end of the 20th century for the Channel Tunnel. After nearly two centuries of dreaming, the island of Great Britain is connected to Continental Europe for the first time since the Ice Age, when the two land masses moved apart.

On May 6, 1994, Britain's Queen Elizabeth II and France's President Mitterrand carried out the official opening. The Queen was accompanied (陪同) on her train journey through the historic tunnel by one of her Rolls-Royce cars which was placed on the train. The following day saw celebrations taking place in Folkestone and Calais. Regular public services did not start until the latter part of 1994.

59. Queen Elizabeth II________ at the opening.

A. took her car Rolls-Royce through the tunnel

B. took her car which was placed on her train through the tunnel

C. took her train through the tunnel 

D. took Mitterrand's train through the tunnel

60. The island of Great Britain is ________.

A. connected to France all the time    B. separated from France with a tunnel

C. separated from France all the time  D. joined to France with the tunnel

61. Which of the following is right?

A. Napoleon made plans for the tunnel.

B. The public could pass through the tunnel by train after May 6, 1994.

C. The tunnel was built for two centuries.

D. The tunnel will do great good to Britain and France.

62. Before 1994, one could go to Britain from France ________.

A. only by ship  B. by ship or plane  C. by car or train  D. by ship, car or train