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所在平台: Udemy |
课程主页: https://www.udemy.com/course/work-and-energy/
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**Coursera课程《物理中的功与能概念》摘要** 本课程专为准备高级国家物理考试、大学水平考试以及各种工程和医学入学考试的学生设计。课程强调了物理学中守恒定律的重要性，特别是能量守恒定律。 **核心内容：** * **守恒定律：** 课程将探讨守恒定律在物理学中的关键作用，阐述某些物理量在粒子或物体经历运动、碰撞和反应等剧烈变化时保持不变的特性。 * **质量守恒：** 将以最简单的形式介绍质量守恒定律，即单个粒子的质量不随其运动或与其他粒子交互而改变。课程将从牛顿第二定律推导出质量守恒，并强调其普遍性，即使在牛顿力学失效的相对论物理学和原子物理学领域也同样适用。 * **能量守恒：** 课程将重点介绍能量守恒定律，并指出迄今为止尚未发现对其的违反。 * **功的概念：** 在深入研究能量守恒之前，课程将引入“功”的概念。“功”与“能量”紧密相关，课程将证明净力对物体所做的功等于物体动能的变化。 * **应用：** 课程将展示如何利用能量守恒定律在难以或不希望通过牛顿第二定律详细计算运动轨迹的情况下，推断粒子或粒子系统的运动特性，尤其适用于所受力不完全确定的情况。 **重要提示：** 18岁以下学习者需在父母或监护人的指导下学习。
Those under 18 may use the services only if a parent or guardian opens their account, handles any enrollments, and manages their account usage. Course on Work Energy and Power is for learners and students preparing for Advance Placement Physics examination and other college level examination. Also students perparing for various engineering and medical entrance examination can also take up couse. Any underage student or learner must take up the course under his/her parent guidance.Conservation laws play an important role in physics. Such laws assert that somequantity is conserved, which means that the quantity remains constant even whenparticles or bodies suffer drastic changes involving motions, collisions, and reactions.One familiar example of a conservation law is the conservation of mass. Expressed inits simplest form, this law asserts that the mass of a given particle remains constant,regardless of how the particle moves and interacts with other particles or other bodies.In the preceding two chapters we took this conservation law for granted, and we treatedthe particle mass appearing in Newton's Second Law (ma = F) as a constant, time independent quantity. More generally, the sum of all the masses of the particles orbodies in a system remains constant, even when the bodies suffer transformations andreactions. This conservation law is one of the most fundamental laws of nature. Although we will derive this law fromNewton's laws, it is actually much more general than Newton's laws, and it remainsvalid even when we step outside of the realm of Newtonian physics and enter the realmof relativistic physics or atomic physics, where Newton's laws fail. No violation of thelaw of conservation of energy has ever been discovered.In mechanics, we can use the conservation law for energy to deduce some features of themotion of a particle or of a system of particles when it is undesirable or too difficult to calculate the full details of the motion from Newton's Second Law. This is especiallyhelpful in those cases where the forces are not known exactly.But before we can deal with energy and its conservation, we must introduce the concept of work. Energy and work are closely related. We will see that the work done bythe net force on a body is equal to the change of the kinetic energy
