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  • 固定速度单位速率

    Can you climb the unit ladder?
    ::你能爬上部队梯子吗?

    Use the interactive below to order the units of measurement along the ladder. The units here measure length but later in this lesson you will use units to measure speed .
    ::使用下面的交互效果来命令沿梯子的测量单位。 这里的单位测量长度, 但在此课中稍后您将使用单位来测量速度 。

     

    INTERACTIVE
    Unit Ladder
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    • Move the red points into the red circles to put the basic SI units into their correct position on the Unit Ladder.
      ::把红色点移到红色圆圈 使基本的SI单位 进入他们在单位梯子上的正确位置
    • Once you have placed them all on the ladder, you can check your work by pressing the white button.
      ::一旦你把它们都放在梯子上, 你可以按白色按钮检查你的工作。
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    Starting at the millimeter, as you go up the list of units, each unit is times larger than the previous.
    ::从毫米开始,当你向上移动单位列表时,每个单位是输入比前一个单位更大的回答倍数。

     

     

    How fast does the train go?
    ::火车开多快?

    lesson content
    Steam Locomotive

    Use the interactive below to look at  the distance that a train goes over time. Afterwards use the information gained in order to answer questions about the train’s rate and speed below.
    ::使用下面的互动式来查看列车经过一段时间的距离。 之后使用所获得的信息回答列车在下面的速度和速度的问题。

     

    INTERACTIVE
    Rate of a Train
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    • Click the white buttons to start and stop the train while recording its distance and time to reach it.
      ::单击白色按钮以启动并停止列车,同时记录列车的距离和到达时间。
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    Discussion Question
    ::讨论问题

    Most of the time people describe the speed of a car or train in miles per hour or kilometers per hour. Why do you think people don't use miles per second or feet per hour in these cases?  Discuss your thoughts with your classmates.
    ::大部分时间人们用每小时英里或每小时公里来描述汽车或火车的速度。 为什么你认为在这些情况下人们不使用每秒或每小时每英尺的英里? 与同学们讨论你的想法。

    CK-12 PLIX Interactive:
    ::CK-12 PLIX 互动:

    You can use this PLIX to show someone's run at a given rate.
    ::您可以使用此 PLIX 显示某人按给定速率运行 。

     

     

     

    How fast is Usain Bolt?
    ::乌赛恩·博尔特有多快?

    lesson content
    On the right: Usain Bolt

    Usain Bolt also known as "Lightning Bolt", i s the fastest sprinter of all time. He ran 100 meters in 9.58 seconds and he ran 200 meters in 19.19 seconds. Which of the two races did he run faster ?
    ::Usain Bolt也被称为“照明宝尔”,是所有时间中最快的冲锋枪。他在9.58秒中跑100米,在19.19秒中跑200米。他跑得更快的是哪一场?

    In the interactive below, use the double number lines  that represent  Usain Bolt’s races in order to compare his speeds over the two races and determine which of the two was a faster rate.
    ::使用代表Usain Bolt种族的双倍数线, 比较他两次赛跑的速度,

     

    INTERACTIVE
    Usain Bolt's Rate
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    The double number lines model both of Usain Bolt's races.
    ::Usain Bolt两场比赛的双倍数线模型

    • Drag the red points to pick a time he runs.
      ::拖曳红色点以选择他运行的时间 。
    • Press the buttons to see how far he runs at the rate of the races. 

      ::按下按钮,看看他跑多远 以赛跑速率。
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    Discussion Question
    ::讨论问题

    1. Breaking Usain Bolt's run time down to 1 second can be described with a mathematical operation . What math do you perform to go from his total run time to 1 second? 
      ::打破 Usain Bolt 的运行时间降为 1 秒, 可以用数学操作来描述。 您用什么数学来计算他的总运行时间降为 1 秒 ?
    2. What math do you perform to go from his total distance run to the distance he ran in 1 second?
      ::你算什么数学? 从他总距离跑到他一秒内跑的距离?

    Try This !  Time yourself running or walking 100 meters at a constant pace. Determine your speed.
    ::尝试这个! 时间在100米以恒定的速度运行或行走。 确定您的速度 。

       

    How  often is there a full moon ?
    ::月圆的频率是多少?

    There are 5 full moons every 148 days. Use the interactive below to visualize the moon’s path around the earth and determine the rate of each phase of the moon over time.  Notice how the moon  appears to us in relation to its position around our planet .
    ::每148天就有5个满月。 利用下面的互动来观察月球环绕地球的路径并确定月球各个阶段的时速。 注意月球相对于地球位置的外观。

     

    INTERACTIVE
    Lunar Phases
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    The Moon completes one revolution around the Earth about every month. From Earth, we can see different phases of the lunar cycle which are based on the location of the Moon in its orbit.
    ::月球大约每个月都会完成一次环绕地球的革命。从地球,我们可以看到月球周期的不同阶段,这些阶段以月球在其轨道上的位置为基础。

    • Drag the red point along the line to see what the Moon looks like at different phases. 
      ::沿着线条拖动红色点以观察月亮在不同阶段的长相。
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       Summary
    ::摘要

    • A unit rate is the amount of one quantity for every 1 unit of another quantity.
      ::A单位费率是每1个单位的1个数量,再1个单位的1个数量。
    • Some examples of constant speed unit rates are miles per hour, kilometers per second, and meters per second.
      ::一些不变速度单位费率的例子为每小时英里、每秒公里、每秒米。
    • Divide the numerator of a fraction by the denominator to find the unit rate.
      ::将一个分数的分子除以分母以找到单位速率。