大学物理学.pptx

高等教育出版社出版高等教育出版社出版Chapter 1.Introduction2Getting prepared!Chapter 1.IntroductionChapter 1.Introduction3You are about to begin what could be one the most exciting course that you will undertake in university.It offers you the opportunity to learn what makes our world“tick”and to gain insight into the role physics plays in our everyday lives.Hey!Chapter 1.Introduction4 About the course Mechanics and ThermodynamicsText book:Physics for Scientists and Engineers with Modern Physics(Third Edition)Chapter 1.Introduction5Feature of text book(1).True style of U.S.University pay attention to pick interest and motivate desire to read book:(2).The best way to promote your ability of expression in English by reading original edition of English book.“We will see many examples in this book of how physics is useful in other fields,and in everyday life.”Chapter 1.Introduction6 References大学物理学（第一册）大学物理学（第一册）力学力学大学物理学（第三册）大学物理学（第三册）热学热学大学物理学（第四册）大学物理学（第四册）波动与波动与光学光学 清华大学出版社清华大学出版社 张三慧张三慧 主编主编大学物理学习指导大学物理学习指导 苏州大学出版社苏州大学出版社Chapter 1.Introduction7Some scalars are always positive,whereas others such as electric charge can be positive or negative.ordinary algebraic quantity that has no direction,or,a number.(mass,time,energy,temperature,)Scalar:Scalars and Vectors(P 44)Chapter 1.Introduction8Vectors follow certain vector rules of combination.quantity that has both direction and magnitude,or,a number and a direction associated with it(displacement,velocity,acceleration,force,etc.)Vector:Chapter 1.Introduction9Adding Vectors GraphicallyThe vector sum is the vector that extends from the tail of one vector to the head of the other vector-tail-to tip method of adding vectors.-commutative law for vector sumChapter 1.Introduction10Subtracting Vectors GraphicallyThe difference between two vectors is the vector that extends from the head of the 2nd vector to the head of the 1st vector.Chapter 1.Introduction11Components of vectors A component of a vector is the projection of the vector on an axis.This component may be in two or three dimensional coordinate system.Both pairs of values contain the same information.is resolved to and ,oyxChapter 1.Introduction12Unit vectors For a fixed Cartesian system,Unit vectors:An advantage of using vector components is that complicated vector problems can be replaced by algebraic manipulation.In the coordinate system,Coordinate system can be chosen freely.unit magnitude,only indicate directionsChapter 1.Introduction13 (1)The Scalar(Dot)Product:Multiplying a Vector by a VectorThe magnitude of :Chapter 1.Introduction14(2)The Vector(Cross)Product Direction is as the figure showing.