13.11 轮轮和轴轴
章节大纲
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Did you ever ride on a Ferris wheel like this one? If you did, then you know how thrilling the ride can be. The faster it goes, the more exciting it is. A Ferris wheel is an example of a called a wheel and axle.
::你曾经骑过这样的摩天轮吗?如果你骑过,那么你知道这车会有多刺激。它越快,就越令人兴奋。一个摩天轮就是一个叫轮和车轴的例子。Round and Round It Goes
::圆圆转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转转A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other. Both rings or cylinders turn in the same direction around a single center point. The inner ring or cylinder is called the axle, and the outer one is called the wheel. Besides the Ferris wheel, the doorknob in the Figure is another example of a wheel and axle.
::方向盘和轴轴是一个简单的机器,由两个连接的环或圆筒组成,一个在另一个在另一个内。两个环或圆筒都朝同一个方向朝一个中点方向旋转。内环或圆筒称为轴轴,外环称为轮。除Ferris轮外,图中的门把手是另一个方向盘和轴的例子。In a wheel and axle, force may be applied either to the wheel or to the axle. This force is called the input force. A wheel and axle does not change the direction of the input force. However, the force put out by the machine, called the output force, is either greater than the input force or else applied over a greater .
::在方向盘和轴轴中,可以对方向盘或轴力施用武力。这种武力被称为输入力。方向盘和轴力不会改变输入力的方向。然而,机器所释放的力量,称为输出力,要么大于输入力,要么超过输入力。Q : Where is the force applied in a Ferris wheel and a doorknob? Is it applied to the wheel or to the axle?
::问题:Ferris车轮和门把手的强度在哪里?是用在方向盘还是用在轴上?A : In a Ferris wheel, the force is applied to the axle by the Ferris wheel’s motor. In a doorknob, the force is applied to the wheel by a person’s hand.
::A:在Ferris轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式轮式Mechanical Advantage of a Wheel and Axle
::轮轮和轴轮的机械优势The of a machine is the factor by which the machine changes the input force. It equals the ratio of the output force to the input force. A wheel and axle may either increase or decrease the input force, depending on whether the input force is applied to the axle or the wheel.
::机器是机器改变输入力的因素。它等于输出力与输入力之比。方向盘和轴可以增加或减少输入力,这取决于输入力是应用到轴还是应用到方向盘。-
When the input force is applied to the axle, as it is with a Ferris wheel, the wheel turns with less force. Because the output force is less than the input force, the mechanical advantage is less than 1. However, the wheel turns over a greater distance, so it turns faster than the axle. The
of the wheel is one reason that the Ferris wheel ride is so exciting.
::当输入力被应用到轴上时,就像用Ferris轮一样,方向盘转动力较小。由于输出力小于输入力,机械优势小于1。然而,方向盘转动的距离大于轴,因此转动速度快于轴。轮子转动是Ferris轮滑动如此令人兴奋的原因之一。 -
When the input force is applied to the wheel, as it is with a doorknob, the axle turns over a shorter distance but with greater force, so the mechanical advantage is greater than 1. This allows you to turn the doorknob with relatively little effort, while the axle of the doorknob applies enough force to slide the bar into or out of the doorframe.
::当输入力应用到方向盘上时,就像用门把手一样,轴转过一个较短的距离,但力更大,因此机械优势大于1,这样你就能够以相对较少的力气把门把手转动,而门把手的轴力足以把铁棒滑进或滑出门框。
Summary
::摘要-
A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other, which both turn in the same direction around a single center point.
::方向盘和轴是一个简单的机器,由两个互相连接的环或圆筒组成,一个在另一个在另一个内,两个向同一个方向朝一个中心点转。 -
A wheel and axle may either increase or decrease the input force, depending on whether the input force is applied to the axle or the wheel. Therefore, the mechanical advantage of a wheel and axle may be greater than 1 or less than 1.
::车轮和车轴可能增加或减少输入力,这取决于输入力是应用于轴还是用于轮。因此,车轮和车轴的机械优势可能大于1或小于1。
Review
::回顾-
Describe a wheel and axle.
::描述方向盘和轴轴。 -
Give an example of a wheel and axle that isn’t mentioned in the article.
::举例来说, 文章中没有提到车轮和车轴。 -
When you pedal a bicycle, you apply force to the back wheel and axle. Is the force applied to the wheel or to the axle? What is the mechanical advantage of the bicycle wheel and axle?
::当你踏脚踏车时,你对后轮和车轴施压。这是对车轮还是车轴施压吗?自行车轮和车轴的机械优势是什么?
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When the input force is applied to the axle, as it is with a Ferris wheel, the wheel turns with less force. Because the output force is less than the input force, the mechanical advantage is less than 1. However, the wheel turns over a greater distance, so it turns faster than the axle. The
of the wheel is one reason that the Ferris wheel ride is so exciting.
