1kinematics-1课件.pptVIP

Chapter 1 ;§1-1 displacement and path;Position Vector;Displacement ;Path;Vectors scalars;Some properties of vectors;3. subtraction;Displacement vs. Path;2. Expression of position vector and displacement;Right-angled Coordinates System ;Polar coordinates system (?,?) Ball coordinates system (R,?, ? );column coordinates system (R, ?, z );Magnitude of the position vector;Example: A hiker begins a two-day trip by first walking 25.0 km due southeast from her car. She stops and sets up her tent for the night. On the second day she walks 40.0 km in a direction 60.0o north of east, at which she discovers a forest ranger’s tower. (a) determine the hiker’s displacements on the first and second day. (b) determine the hiker’s total displacement and path.;Solution set up a plane right-angled coordinate, denoting the displace-ment vectors on the first and second days by A and B, respectively.;car;car;(b) The total path of the hiker: ;§1-2 velocity and speed;Average speed;Linear speed and angular speed