This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Chapter 11 Chapter 11 Kinematics of Particles Kinematics of Particles EMEC 3730 Fall 2007 niversity of Nebraska University of Nebraska 1 11.1 Introduction Definitions: i ti d f th t f ti Ki ti i d t Kinematics : study of the geometry of motion. Kinematics is used to relate displacement, velocity, acceleration, and time without reference to the cause of motion. Kinetics : study of the relations existing between the forces acting on a body, the mass of the body, and the motion of the body. Kinetics is used to predict the motion caused by given forces or to determine the forces required to produce a given motion. Rectilinear motion: position, velocity, and acceleration of a particle as it moves along a straight line. Curvilinear motion : position, velocity, and acceleration of a particle as it moves along a curved line in two or three dimensions. 2 11.2 Rectilinear Motion: Position, Velocity &amp; Acceleration , y Particle moving along a straight line is said be in ctilinear motion to be in rectilinear motion . Position coordinate of a particle is defined by positive or negative distance of particle from a fixed origin on the line. The motion of a particle is known if the p position coordinate for particle is known for every value of time t . Motion of the particle may be expressed in the form of a function, e.g., 3 2 6 t t x = or in the form of a graph x vs. t . 3 11.2 Rectilinear Motion: Position, Velocity &amp; Acceleration , y Consider particle which occupies position P at time and P at + Dt , t x = Average velocity Instantaneous velocity may be positive or egative Magnitude of velocity is referred t x v t = = lim Instantaneous velocity negative. Magnitude of velocity is referred to as particle speed . From the definition of a derivative, dt dx t x v t = = lim e.g., 3 2 6 t t x = 4 2 3 12 t t dt dx v = = 11.2 Rectilinear Motion: Position, Velocity &amp; Acceleration , y Consider particle with velocity v at time t nd t t and v at t + Dt , Instantaneous acceleration t v a t = = lim Instantaneous acceleration may be: positive: increasing positive velocity or decreasing negative velocity negative: decreasing positive velocity or increasing negative velocity. g g y 5 11.2 Rectilinear Motion: Position, Velocity &amp; Acceleration , y From the definition of a derivative, dt x d dt dv t v a t g lim 2 2 2 = = = t dt dv a t t v 6 12 3 12 e.g....
View Full
Document
 Spring '08
 Norton

Click to edit the document details