05 the laws of motion tủ tài liệu bách khoa
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: 05 the laws of motion tủ tài liệu bách khoa
05 the laws of motion tủ tài liệu bách khoa
# PUZZLERThe Spirit ot Akron ts an airship that is more than 60 m long. When It is parked 8t an airport one person can aasty support it overhead usin 05 the laws of motion tủ tài liệu bách khoang a single hand. Nonetheless, it is impossible for even a very strong adult to move the ship abruptly. What property of this huge airship makes It very difficult to cause any sudden changes in its motion? (Cour-tttrofidMrdi Oyten/EH3For n>xe information obout the airship, •is • hnpi//Hww (oodyeor. 05 the laws of motion tủ tài liệu bách khoacon/m/blinp/ indrx.htalchapterThe Laws of MotionChapter Outline5.1The Concept of Force5.2Newton's First Law and Inertial Frames5.3Mass5.4Newton's Seco05 the laws of motion tủ tài liệu bách khoa
nd Law5.5The Force of Gravity and Weight5.6Newton's Third Law5.7Some Applications of Newton's Laws5.8Forces of Friction1105.1 The Concept of Force111■ # PUZZLERThe Spirit ot Akron ts an airship that is more than 60 m long. When It is parked 8t an airport one person can aasty support it overhead usin 05 the laws of motion tủ tài liệu bách khoaght cause one panicle to remain at rest and another particle to accelerate? In this chapter, we investigate what causes changes in motion. The two main factors we need to consider arc the forces acting on an object and the mass of the object. We discuss the three basic laws of motion, which deal wit 05 the laws of motion tủ tài liệu bách khoah forces and masses and were formulated more than three centuries ago by Isaac Newton. Once we understand these laws, we can answer such questions as05 the laws of motion tủ tài liệu bách khoa
"What mechanism changes motion?" and "Why do some objects accelerate more than others?"5.1^ THE CONCEPT OF FORCEEveryone has a basic understanding of # PUZZLERThe Spirit ot Akron ts an airship that is more than 60 m long. When It is parked 8t an airport one person can aasty support it overhead usin 05 the laws of motion tủ tài liệu bách khoaball when you throw or kick it. In these examples, the word forte is associated with muscular activity and some change in the velocity of an object. Forces do not always cause motion, however. For example, as you sit reading this book, the force of gravity acts on your body and yet you remain statio 05 the laws of motion tủ tài liệu bách khoanary. As a second example, you can push (in other words, exert a force) on a large boulder and not lx- able to move it.What force (if any) causes the05 the laws of motion tủ tài liệu bách khoa
Moon to orbit the Earth?' Newton answered this and related questions by stating that forces are what cause any change in the velocity of an object, Th # PUZZLERThe Spirit ot Akron ts an airship that is more than 60 m long. When It is parked 8t an airport one person can aasty support it overhead usin 05 the laws of motion tủ tài liệu bách khoa constant because it moves in a nearly circular OI bit around the Earth. We now know that this change in velocity is caused bv the force exerted on the Moon by the Earth. Because only a force can cause a change in velocity, we can think of force as that which r«f«« a My to accelerate. In this chapte 05 the laws of motion tủ tài liệu bách khoar, we are concerned with the relationship between the force exerted on an object and the acceleration of that object.What happens when several forces05 the laws of motion tủ tài liệu bách khoa
act simultaneously on an object? In this case, the object accelerates only if the net force acting on it is not equal to zero. The net force acting on # PUZZLERThe Spirit ot Akron ts an airship that is more than 60 m long. When It is parked 8t an airport one person can aasty support it overhead usin 05 the laws of motion tủ tài liệu bách khoace, or the unbalanced force.) If the net force exerted on an object is zero, then the acceleration of the object is zero and its velocity remains constant. That is. if the net force acting on the object is zero. then the object either remains at rest or continues to move with constant velocity. When 05 the laws of motion tủ tài liệu bách khoa the velocity of an object is constant (including the case in which the object remains at rest), the object is said to lx- in equilibrium.When a coile05 the laws of motion tủ tài liệu bách khoa
d spring is pulled, as in Figure 5.1a. the spring stretches. When a stationary cart is pulled suíĩicently hard that friction is overcome, as in Figure # PUZZLERThe Spirit ot Akron ts an airship that is more than 60 m long. When It is parked 8t an airport one person can aasty support it overhead usin 05 the laws of motion tủ tài liệu bách khoaass of forces called contact forces. That is. they involve physical contact between two objects. Other examples of contact forces are the force exerted by gas molecules on the walls of a container and the force exerted by your feet on the floor.Another class of forces, known as field forces, do not 05 the laws of motion tủ tài liệu bách khoainvolve physical contact between two objects but instead act through empty space. The force of gravitational attraction between two objects, illustrat05 the laws of motion tủ tài liệu bách khoa
ed in Figure 5.Id, is an example of this class of force. This gravitational force keeps objects bound to the Earth. The plan-A body accelerates becaus # PUZZLERThe Spirit ot Akron ts an airship that is more than 60 m long. When It is parked 8t an airport one person can aasty support it overhead usin 05 the laws of motion tủ tài liệu bách khoated on the object within the boxed area. Some agent ill the environment external to the boxed area exerts a force on the object.ets of our Solar System arc bound to the Sun by the action of gravitational forces. Another common example of a field force is the electric force that one electric charge e 05 the laws of motion tủ tài liệu bách khoaxerts on another, its shown in Figure 5.1e. These charges might be those of the election and proton that foim a hydrogen atom. A third example of a fi05 the laws of motion tủ tài liệu bách khoa
eld force is the force a bar magnet exerts on a piece of iron, ns shown in Figure 5.If. I he forces holding an atomic nucleus together also arc field # PUZZLERThe Spirit ot Akron ts an airship that is more than 60 m long. When It is parked 8t an airport one person can aasty support it overhead usin 05 the laws of motion tủ tài liệu bách khoaNewton, were uneasy with the idea that a force can act between two disconnected objects. To overcome this conceptual problem. Michael Faraday (1791-1867) introduced die concept of a field. According to this approach, when object 1 is placed at some point Pncar object 2, we say that object 1 interact 05 the laws of motion tủ tài liệu bách khoas with object 2 by virtue of the gravitational field that exists at p. The gravitational field al Pis created bv object 2. Likewise, a gravitational f05 the laws of motion tủ tài liệu bách khoa
ield created by object 1 exists al the position of object 2. In fact, all objects create a gravitational field in the space around themselves.The dist # PUZZLERThe Spirit ot Akron ts an airship that is more than 60 m long. When It is parked 8t an airport one person can aasty support it overhead usin 05 the laws of motion tủ tài liệu bách khoatomic level, all die forces we classify as contact forces turn out to be caused by # PUZZLERThe Spirit ot Akron ts an airship that is more than 60 m long. When It is parked 8t an airport one person can aasty support it overhead usinGọi ngay
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