问题 填空题

一个质量为2kg的物体在合外力F的作用下从静止开始运动。合外力F随时间t变化的关系如图示,则物体匀加速运动的加速度大小为      , 速度达到最大值的时刻是       .

答案

5m/s2 ,15s

题目分析:当物体所受合外力恒定不变时做的是匀变速直线运动,所以在5-10s时加速度恒定不变,为55m/s2 ,合外力方向一直为正值,物体一直向着正方向加速,所以在15s时速度最大

点评:速度的变化由力与速度的方向决定,加速度的变化由合外力的大小决定

阅读理解

LONDON—Archaeologists have discovered a smaller prehistoric(史前) site near Britain’s famous circle of standing stones at Stonehenge.

Researchers have named the site “Bluehenge” after the color of the 27 Welsh stones that were laid to make up a path. The stones have disappeared, but the path of holes remains.

The new circle, unearthed over the summer by researchers from Sheffield University, represents an important find, researchers said Saturday. The site is about a mile away from Stonehenge.

Bluehenge, about 80 miles southwest of London, is believed to date back to about the time Stonehenge was built, about 5,000 years ago.

Mike Parker Pearson of Sheffield University said he believed the path and stonehenge itself were linked to rituals(仪式) of life and death.

Mike Parker suggested that the ancient funerary rituals began at a different circle site known as “Wood-henge”, which represented the world of the living. The bodies of the dead were then brought down the River Avon to Bluehenge, which represented death, and were finally carried along a ceremonial route known as the Avenue to Stonehenge.

Bournemouth University Professor Tim Darvill, an expert on Stonehenge, told Britain’s Dail Mail that Bluehenge “adds to the richness” of the ancient site’s story.

“This henge is very important because it forms part of the picture of ceremonial monuments in the area and puts Stonehenge into context,” Darvill was quoted(引述) as saying. “It’s no longer Stonehenge standing alone, but it has to be seen in context with the landscape.”

小题1:How many henges are mentioned in this passage?

A.Two

B.Three

C.Four

D.Five小题2:Who believed the Stonehenge is related to ancient ritual of death?

A.Archaeologists from London

B.Welsh researchers

C.Mike Parker Pearson

D.Professor Tim Darvill小题3:What does the underlined sentence “It’s no longer Stonehenge standing alone, but it has to be seen in context with the landscape.” in the last paragraph mean?

A.Stonehenge has noting to do with Bluehenge

B.Woodhenge represented the world of living in ancient times.

C.Bluehenge represented death

D.Stonehenge, Woodhenge and Bluehenge should be studied together小题4:From the passage we can learn that ______.

A.researchers have named the site “Bluehenge,” because they have found blue huge stones there

B.funerary rituals were carried out along the path starting from Woodhenge, River Avon to Bluehenge, finally Stonehenge.

C.Bluehenge is 1 mile away from London

D.Bluehenge dates back to 2000 BC

单项选择题