题干

如图所示,在竖直向上大小为10N的力F的作用下,重 物A沿竖直方向匀速上升.已知重物A上升速度为0.2m/s,不计滑轮重、绳重及绳与滑轮间的摩擦,则物体A的重力大小为____,滑轮上升的速度为____

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答案(点此获取答案解析)

5N,0.1m/s

同类题2

阅读下列短文,从每小题所给的A、B、C、D四个选项中选出一个最佳选项。

    Answers to life can be found in everyday events. Watching nature, watching people and watching animals communicate with each other provide some of the simplest ways to life's biggest problems.

    This became clearer to me yesterday. It caused me to ask myself, “How do I respond (反应) to the storms in life?”

    People usually run when it starts to rain. I love to walk in it, stand on my front door and feel it. I grew up doing it and have never really felt the fear many people do.

    The animal world senses changes in the weather far earlier than humans. My dog, Ricky, begins to shake long before the storm is close enough to be noticed. I was about to feed my three dogs yesterday and as usual, I let them out in the yard first. They didn't move when thunder came across the skies. So I placed their food in their bowls and called Ricky into the kitchen.

    Ricky was just standing there in place next to his bowl. The thunder became louder, which forced him to stop eating his meal. Then I watched Phil. He made his way across the kitchen floor and stood over Ricky's bowl. He ate all the remaining food. Generally, if Ricky was standing there, he wouldn't dare (敢) come close. But today, he took advantage (优势) of the storm and got what he wanted. His hope for the prize outweighed (胜过) his fear of the storm.

    That's when it hit me. As men, we face all kinds of storms. They come in unannounced. Sometimes we stay in a corner or under the blankets, hoping it will all pass. However, if you dare put your head out, you'll discover there're people doing what they must to get what they must have out of life. Isn't it time you decided to take advantage of the storm?