This summary presents an abridged version of the chapter, including the important equations and all available learning aids. For convenient reference, the learning aids (including the text’s examples) are placed next to or immediately after the relevant equation or discussion.

Interactive LearningWare examples are solved according to a five-step interactive format that is designed to help you develop problem-solving skills.	Concept Simulations are animated versions of text figures or animations that illustrate important concepts. You can control parameters that affect the display, and we encourage you to experiment.
Interactive Solutions offer specific models for certain types of problems in the chapter homework. The calculations are carried out interactively.	Self-Assessment Tests include both qualitative and quantitative questions. Extensive feedback is provided for both incorrect and correct answers, to help you evaluate your understanding of the material.

Topic	Discussion	Learning Aids
Displacement	2.1 Displacement   Displacement is a vector that points from an object’s initial position to its final position. The magnitude of the displacement is the shortest distance between the two positions.
	2.2 Speed and Velocity
Average speed	The average speed of an object is the distance traveled by the object divided by the time required to cover the distance:   (2.1)	Example 1
Average velocity	The average velocity of an object is the object’s displacement Dx divided by the elapsed time Dt:   (2.2)	Example 2
Instantaneous velocity	Average velocity is a vector that has the same direction as the displacement. When the elapsed time becomes infinitesimally small, the average velocity becomes equal to the instantaneous velocity v, the velocity at an instant of time:   (2.3)
	2.3 Acceleration
Average acceleration	The average acceleration is a vector. It equals the change Dv in the velocity divided by the elapsed time Dt, the change in the velocity being the final minus the initial velocity:   (2.4)	Examples 3, 4, 17   Interactive Solution 2.17
Instantaneous acceleration	When Dt becomes infinitesimally small, the average acceleration becomes equal to the instantaneous acceleration a:   (2.5)   Acceleration is the rate at which the velocity is changing.
Use Self-Assessment Test 2.1 to evaluate your understanding of Sections 2.1, 2.2 and 2.3.
	2.4 Equations of Kinematics for Constant Acceleration
	2.5 Applications of the Equations of Kinematics
Equations of kinematics	The equations of kinematics apply when an object moves with a constant acceleration along a straight line. These equations relate the displacement x–x0, the acceleration a, the final velocity v, the initial velocity v0, and the elapsed time t–t0. Assuming that x0=0 m at t0=0 s, the equations of kinematics are   (2.4)   (2.7)   (2.8)   (2.9)	Examples 5, 6, 7, 8, 9, 18   Concept Simulations 2.1, 2.2   Interactive LearningWare 2.1, 2.2   Interactive Solutions 2.29, 2.31
Use Self-Assessment Test 2.2 to evaluate your understanding of Sections 2.4–2.5.
	2.6 Freely Falling Bodies	Examples 10, 11, 12, 13, 14 and 15
Acceleration due to gravity	In free-fall motion, an object experiences negligible air resistance and a constant acceleration due to gravity. All objects at the same location above the earth have the same acceleration due to gravity. The acceleration due to gravity is directed toward the center of the earth and has a magnitude of approximately 9.80 m/s2 near the earth’s surface.	Concept Simulations 2.3   Interactive Solutions 2.47, 2.49
	2.7 Graphical Analysis of Velocity and Acceleration	Example 16   Concept Stimulation 2.4
Use Self-Assessment Test 2.3 to evaluate your understanding of Sections 2.6–2.7.

Copyright © 2000-2003 by John Wiley & Sons, Inc. or related companies. All rights reserved.