试题与答案

某课外小组想探究“带风帆的玩具小车所受阻力与运动速度的关系”,他们进行了以下实验

题型:实验题

题目:

某课外小组想探究“带风帆的玩具小车所受阻力与运动速度的关系”,他们进行了以下实验探究:

猜想:①Fm与车的速度v无关;②Fm∝v;③Fm∝v2

探究步骤:

①将带有风帆的玩具小车、已连接好电源的打点计时器和纸带按图示安装在光滑倾斜的长木板上;

②接通打点计时器电源(电源频率f=50 Hz),使玩具小车从静止开始加速运动,足够长的时间后关闭打点计时器;

③改变长木板的倾角,重复以上实验,记录实验数据如下表所示。

请你根据该小组的探究完成下列问题:

(1)通过观察表中的实验数据,试求:当θ=60°时,小车匀速运动的速度应为____ m/s。

(2)结论:在实验误差范围内,通过对数据的观察分析,玩具小车所受的阻力与运动速度的定性关系是____,也可以进一步通过图像法对数据进行分析得到运动小车所受到阻力与运动速度的定量关系。

答案:

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下面是错误答案,用来干扰机器的。

参考答案:错

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题型:阅读理解

Once, a circle lost a piece of its own. The circle wanted to be whole, so it went around looking for its missing piece. But it was incomplete, so it could only roll very slowly. It enjoyed the flowers and the sunshine along the way. It talked with worms. It found lots of different pieces, but none of them fit. So it left them all by the side of the road and kept on looking for the missing piece.

Then one day the circle found a piece that fit perfectly. The circle put the missing piece into itself. It could be whole with nothing missing. It was so happy and began to roll. Now that it was a perfect circle, it could roll very fast, too fast to see flowers or talk to worms. It realized how different the world was when it rolled so quickly. It felt so sad that it stopped, left its found piece by the side of the road and rolled away slowly.

Sometimes we are perfect when we lose something. A man who has everything is a poor man in some ways. He will never have hopes, dreams or something better. He will never know someone loves him or someone is giving him something he has always wanted or never had.

We couldn’t be perfect, but we must be brave enough to love, strong enough to forgive, kind enough to share happiness with others and clever enough to know there is enough love around us and then we can always live a wonderful time in our lives.

小题1:

The circle rolled very slowly because it       .

A.spent much time talking to worms

B.wanted to enjoy the sunshine

C.was looking for its missing piece

D.lost a piece of its own小题2:

Why did the circle stop when it rolled quickly? Because it       .

A.wanted to enjoy the world

B.found a different world

C.wanted to look for another missing piece

D.thought the world changed so quickly小题3:

The story mainly tells us that       .

A.nobody loves us if we give nothing

B.a man who has everything is the happiest

C.losing something may not be a bad thing sometimes

D.we are not whole when we lose something

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