66 Force and Motion-Mid

Force and Motion Written by Ron Fridell

力与运动Ron Fridell著

Introduction Each word above tells how objects can move. Some travel in a straight, flat line such as a ball rolled along the ground. When you kick the ball into the air, it flies in a curved path until it bounces on the ground. A merry-go-round turns in circles, while lightning strikes in a jagged path. Motion is all around you. It's even inside you as your blood moves through your body. For every motion, there is a force. In this book, you will learn about the forces that make things move, stop, and change direction or speed.

上面的每个单词都告诉我们物体是如何移动的。 有些以直线运动，如沿着地面滚动的球。 当你把球踢向空中时，它会沿着弯曲的路径飞行，直到在地面上反弹。 旋转木马在转圈，闪电在锯齿状的道路上划过。 运动就在你周围。甚至当你的血液流经你的身体时，它也在你体内。 对于每个运动，都有一个力。 在这本书中，你将了解使事物移动、停止和改变方向或速度的力。

Motion Needs a Force To make something move, a force is needed. Lifting, pushing, and pulling are all forces. At times, a person provides the force. When you lift a stack of books, push a broken-down car, or pull a rope in a tug-of-war game, you are the force.

要使某物移动，就需要一个力。 提、推、拉都是力。 有时，一个人提供了力量。 当你搬起一堆书，推一辆抛锚的汽车，或者在拔河比赛中拉一根绳子时，你就是那股力量。

Machines can provide force to create motion. A huge engine can produce enough force to propel a massive rocket into space. Motors in cake mixers, fans, and blenders use electrical force to make things move. Nature can also be a strong force. Breezes make leaves dance in the treetops. Ocean waves make boats bob up and down. Forces deep underground cause earthquakes that make the ground tremble.

机器可以提供力量来产生运动。 一个巨大的发动机可以产生足够的力量推动一个巨大的火箭进入太空。 蛋糕搅拌机、风扇和搅拌机中的马达利用电力来推动物体运动。 自然也可以是一种强大的力量。 微风吹得树叶在树梢上翩翩起舞。 海浪使船只上下颠簸。 地下深处的力量引起地震，使地面颤抖。

The Laws of Motion Much of what we know about motion comes from scientists who lived hundreds of years ago. They conducted tests on moving objects. British scientist Isaac Newton discovered gravity the invisible force that causes things to fall toward the ground. You may have heard that he was sitting under a tree one day when a falling apple hit him on the head. The story goes that this accident led him to discover gravity. Isaac wasn't really hit on the head by a falling apple. That's just a myth. But over time, he observed that objects always fall down toward the ground. And that led him to discover gravity. SIR LSAAC NEWTON (1642-1727) Isaac Newton lived on a farm in England. Instead of farming, he chose to study math and science in London. At age 27, Isaac did experiments with light He was the first to suggest that light. was actually made up of all the colors of the rainbow He is now one of the most famous scientists of all time!

运动定律我们对运动的了解大部分来自生活在几百年前的科学家。 他们对移动物体进行测试。 英国科学家艾萨克·牛顿发现了万有引力，这是一种无形的力量，可以使物体落向地面。 你可能听说过，有一天他坐在树下，一个掉落的苹果砸在了他的头上。 据说，这次意外使他发现了万有引力。 艾萨克的头并不是被掉落的苹果击中的。 这只是一个神话。但随着时间的推移，他观察到物体总是朝着地面下落。 这让他发现了重力。 艾萨克·牛顿爵士(1642-1727)艾萨克·牛顿住在英国的一个农场。 他没有选择务农，而是选择在伦敦学习数学和科学。 27岁时，以撒用光做实验，他是第一个提出光的人。 实际上是由彩虹的所有颜色组成的。他现在是有史以来最著名的科学家之一!

Newton's First Law of Motion Isaac Newton is known for his three laws of motion, which explain how things move. The first part of the first law says that an object at rest will remain at rest unless a force acts upon it. For example, your bike will stay parked where it is unless something moves it. The second part of this law states that an object in motion will continue moving in the same way unless a new force changes the motion. It will keep moving at the same speed and in the same direction. So your moving bike will continue moving at the same speed and in the same direction until you pedal faster, coast, brake, or turn. Word Wise In government, a law is a rule that people must obey. In science a law is a statement that explains how things always work in the physical world.

牛顿第一运动定律艾萨克·牛顿以他的三大运动定律而闻名，这些定律解释了物体是如何运动的。 第一定律的第一部分说，静止的物体将保持静止，除非有一个力作用在它上面。 例如，你的自行车会一直停在原地，除非有什么东西移动它。 该定律的第二部分指出，运动中的物体将继续以相同的方式运动，除非有新的力改变运动。 它会以相同的速度和方向移动。 所以你的自行车将继续以相同的速度和方向移动，直到你踩得更快，滑行，刹车或转弯。 在政府里，法律是人们必须遵守的规则。 在科学中，定律是解释物质世界中事物如何运行的一种陈述。