物理专业英语lecture-review.doc

Chapter 1. Vectors and Scalars Units（International , dimensions), Scalars，Vectors, Adding vectors, parallelogram of vectors, multiplying vectors, components, equilibrium 重点：Addition，Subtraction and Production of Vector 难点：scalar product,vector product Chapter 2 Motion and Momentum I.Fundamental Laws of Motion(Newtons Law of Motion) a) Newtons first Law of Motion (the law of inertia ) An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. b) Newtons Second Law of Motion Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object).  orFORCE = MASS times ACCELERATION Everyone unconsciously knows the Second Law. Everyone knows that heavier objects require more force to move the same distance as lighter objects. c) Newtons third Law of Motion For every action there is an equal and opposite re-action. This means that for every force there is a reaction force that is equal in size, but opposite in direction. That is to say that whenever an object pushes another object it gets pushed back in the opposite direction equally hard. ii) Drawing Free-Body Diagrams Free-body diagrams are diagrams used to show the relative magnitude and direction of all forces acting upon an object in a given situation. The only rule for drawing free-body diagrams is to depict all the forces that exist for that object in the given situation. Thus, to construct free-body diagrams, it is extremely important to know the various types of forces. iii) Types of Forces A force is a push or pull acting upon an object as a result of its interaction with another object. Contact Forces Action-at-a-Distance Forces Frictional Force Gravitational Force Tension Force Electrical Force Normal Force Magnetic Force Air Resistance Force Applie