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  • 机器机机

    Examples of machines: a chainsaw cutting a tree and construction equipment at a site.

    When you hear the word , do you think of power tools or construction equipment, like the ones pictured above? While both of these examples are machines, you might be surprised to learn that devices as simple as hammers and screws are also machines.
    ::当你听到这个词时,你是否想到像上面所描述的那样的动力工具或建筑设备?虽然这两个例子都是机器,但你可能会惊讶地知道,像锤子和螺丝一样简单的装置也是机器。

    Q : Why are simple tools considered to be machines?
    ::问:为什么简单工具被认为是机器?

    A : Like all machines, they change forces and make work easier.
    ::A:和所有机器一样,它们改变了力量,使工作更加容易。

    What Is A Machine?
    ::"机器"是什么?

    A machine is a device that helps us do work more easily - work is done whenever a force moves an object over a . A machine can be anything from a simple tool like a hammer or a screwdriver to a complex gadget like a car or a computer. Machines are designed to change how we apply forces and motions so that we can do tasks that would be too hard, too dangerous, or impossible to do without them. The amount of work done is represented by the equation:
    ::机器是一种能帮助我们更轻松地工作的装置, 每当一股力量将物体移动到一个物体上时, 机器就会完成工作。 机器可以是简单的工具, 从锤子或螺丝起子到像汽车或计算机这样的复杂装置。 机器的设计是要改变我们如何运用力和动作, 以便我们能完成那些太难、太危险或没有它们是不可能完成的任务。 完成的工作量由方程式表示 :

    Work = Force x Distance
    ::工作=强制x距离

    When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. The output force may or may not be the same as the input force. The force you apply to the machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance.  
    ::当您使用机器时,您会对机器施压。这支力被称为输入力。这支力又被称作输入力。这支力被称作输出力。这支力被称作输出力。输出力可能与输入力相同,也可能与输入力不同。你对机器施压的力被应用在一个给定的距离上,称为输入距离。机器对物体施压的力也被应用到一个距离上,称为输出距离。输出距离可能与输入距离相同,也可能与输入距离不同。

    How Machines Make Work Easier
    ::机器如何使工作更加容易

    Contrary to popular belief, machines do not increase the amount of work that is done. They just change how the work is done. Machines make work easier by increasing the amount of force that is applied, increasing the distance over which the force is applied, or changing the direction in which the force is applied. 
    ::与大众的信仰相反,机器不会增加完成的工作量,而只会改变工作的方式。 机器通过增加所应用的武力、增加使用武力的距离或改变使用武力的方向而使工作更加容易。

    Q : If a machine increases the force applied, what does this tell you about the distance over which the force is applied by the machine:
    ::问题:如果机器增加应用的力, 如何说明机器使用力的距离:

    A : The machine must apply the force over a shorter distance. That’s because a machine doesn’t change the amount of work and work equals force times distance. Therefore, if force increases, distance must decrease. For the same reason, if a machine increases the distance over which the force is applied, it must apply less force.
    ::甲:机器必须用更短的距离来应用力力。 这是因为机器不会改变工作量和工作等于力时距离。 因此,如果增加力,距离必须降低。 出于同样的原因,如果机器增加力力的距离,它必须降低力力力。

    Increasing Force
    ::增强力力

    The output force of a machine can be increased by increasing the distance a force is applied by the user. Examples of machines that increase force are steering wheels and pliers (see Figure ). Read below to find out how both of these machines work. In each case, the machine applies more force than the user applies to the machine, but the machine applies the force over a shorter distance.
    ::机器的输出力可以通过提高用户的距离来增加。 增强力的机器的例子有方向轮和钳(见图 ) 。 阅读下文以了解这两台机器是如何运作的。 在每种情况下,机器的输出力都比用户对机器应用的要强,但机器对更短的距离应用力。

    Turning a steering wheel causes the smaller steering column in the center of the wheel to turn. The steering column turns a shorter distance but with more force. This can then turn the wheels of the car.
    ::方向盘转动方向盘使方向盘中心较小的方向盘柱转动。 方向盘转动的距离较短, 但力势更大。 这样可以转动汽车轮子 。

    When you press together the two handles of the pliers, it causes the other ends of the pliers to squeeze an object. The handles you squeeze move a greater distance than the squeezing end, but the squeezing end applies more force. This means that using pliers can allow you to squeeze objects harder than with your fingers.
    ::当您一起按住钳子的两个把手时,它会使钳子的另外两端挤压一个物体。你挤压的把手移动的距离大于挤压的端,但挤压的端施加的力更大。这意味着使用钳子可以使您比手指更用力地挤压物体。

    Steering wheel and pliers demonstrating how machines increase force over distance applied.

    Increasing Distance
    ::增加距离

    The distance the force acts over can be increased by using machines - here, the trade-off is the amount of force the machine applies is lower than the force applied to the machine. Examples of machines that increase the distance over which force is applied are leaf rakes and hammers (see Figure ). Read below to find out how these two machines work. In each case, the machine increases the distance over which the force is applied, but it reduces the strength of the force.
    ::使用机器可以增加力力作用的距离 - 这里, 权衡是机器应用的力力比对机器应用的力小。 增加力力作用距离的机器的例子有叶片和锤子(见图 )。 下面阅读以了解这两台机器是如何工作的。 在每种情况下,机器会增加力力作用的距离,但它会降低力力。

    When a person applies force to the handle end of a rake, they move it over a short distance. The other end of the rake moves over a greater distance but with less force. This allows the person to cover more ground with the rake.
    ::当一个人用武力对着一只浣熊的把手端施压时,它们会将它移到很短的距离上。 浣熊的另一端会移动到更远的距离上, 但却没有那么大的力量。 这样可以让一个人用浣熊覆盖更多的地面。

    When a carpenter moves the handle of the hammer back and forth a short distance with a strong force, the head of the hammer moves a greater distance back and forth against the nail but with less force. The hammer drives the nail into the board by repeatedly hitting the nail.
    ::当木匠用强力把锤子的柄向前移动时,锤子的头向前和向前移动的距离要大于钉子,但用较少的力。 锤子反复敲钉,把钉子推入板上。

    A woman using a rake and a carpenter hammering a nail into wood.

    Changing the Direction of Force
    ::改变部队方向

    Some machines change the direction of the force applied by the user. They may or may not also change the strength of the force or the distance over which the force is applied. Two examples of machines that work this way are the claw ends of hammers and flagpole pulleys. You can see in the Figure how each of these machines works. In both cases, the direction of the force applied by the user is reversed by the machine.
    ::有些机器改变了用户所施力的方向, 也可能不会改变力的力量力或力力力的距离。 有两个机器可以这样运作的例子是锤子和旗杆滑轮的爪子端。 您可以从图中看到这些机器是如何运作的。 在这两种情况下, 用户所施力的方向都被机器颠倒了 。

    When someone uses the claw end of the hammer to remove a nail stuck in some wood, the hammer's claw pushes up on the nail as they push down on the handle. The hammer changes the direction of the force. Also, in this case, the person is moving the handle a greater distance than the claw end of the hammer moves, and so a greater force is applied to the nail. 
    ::当有人用锤子的爪子端去掉一些木头中的钉子时, 锤子的爪子会按在钉子上, 当他们按在把手上时。 锤子会改变力量的方向。 另外, 在这个例子中, 人移动把手的距离比锤子动作的爪子端要远, 所以对钉子施加更大的力。

    The flagpole's rope wraps around a which is a wheel with a groove in the rime. If someone pulls down on one end of the rope, the other end pulls up. A simple pulley does not change the amount of force or distance over which the force is applied.
    ::旗杆的绳索环绕着一个轮子,轮子上有一个弯曲。 如果有人从绳子的一端拉下来, 另一端就会拉上来。 简单的滑轮不会改变所施力的强度或距离 。

    A hammer claw removing a nail and a person using a flagpole pulley.

    Q : If the pulley only changes the direction of the force, how does it make the work of raising the flag easier?
    ::问:如果滑轮只改变部队方向,如何使升旗工作更容易?

    A : The pulley makes it easier to lift the flag because it allows a person to pull down on the rope and add his or her own to the effort, rather than simply lifting the load.
    ::A:滑轮使升旗更加容易,因为它允许一个人拉下绳索,加插他或她自己的努力,而不是简单地卸载。

    Simple and Compound Machines
    ::简单机和复合机

    There are six types of simple machines that make up the basic building blocks of all other machines: 
    ::有六种简单的机器构成所有其他机器的基本构件:

    • ,
    • ,
    • ,
    • ,
    • pulley, and
      ::滑轮,和
    • . 

    The six types are pictured in the Figure . Simple machines consist of a single mechanical part and work by changing the direction or size of an applied force. You’ve probably used some of these simple machines yourself. machines, on the other hand, are devices that consist of two or more simple machines working together to perform a specific task. Compound machines are more complex than simple machines and can perform a wider range of tasks. Examples of compound machines include bicycles, cars, and washing machines.
    ::这六种类型在图中都有图解。简单机器由一个机械部件组成,通过改变应用力的方向或大小来工作。你可能自己使用过其中一些简单机器。 另一方面,机器是由两台或两台以上简单机器组成的装置,它们共同执行特定任务。复合机器比简单的机器复杂得多,可以执行更广泛的任务。复合机器的例子包括自行车、汽车和洗衣机。

    Types of simple machines and a compound machine, including a wheelbarrow.

     

    Watch this video to learn more about simple machines:
    ::观看这段影片以了解更多简单的机器:

     

     

    Summary
    ::摘要

    • A machine is any device that makes work easier by changing a force.
      ::机器是任何能通过改变力使工作更轻松的装置。
    • Machines may increase the strength of the force, increase the distance over which the force is applied, or change the direction in which the force is applied.
      ::机器可能增加部队的兵力,增加部队的距离,或改变部队的部署方向。
    • There are six types of simple machines. Machines that consist of two or more simple machines are called compound machines.
      ::有六类简单机器,由两台或两台以上简单机器组成的机器称为复合机器。

    Review
    ::回顾

    1. What is a machine?
      ::什么是机器? 机器吗? What is a machine?
    2. List three ways that machines may change a force.
      ::列出机器可以改变力量的三种方式。
    3. Can a machine increase both the force and the distance over which the force is applied? Why or why not?
      ::机器能增加力力和施用力的距离吗?为什么或为什么不能?
    4. A broom is an example of a machine. Where are the input and output forces applied?
      ::扫帚是机器的一个例子。 输入力和输出力在哪里应用?
    5. Look at the pictures of simple machines in the Figure . Which type of simple machine is represented by each of the following tools?
      1. hammer
        ::锤子
      2. ladder
        ::梯阶梯
      3. knife
        ::刀刀
      4. doorknob
        ::门把手

      ::查看图中简单机器的图片。以下工具代表哪类简单机器? 锤子梯刀门把手