Presentation on theme: "Physics Principles and Problems"— Presentation transcript:
1 Physics Principles and Problems Representing MotionChapter 2Physics Principles and ProblemsZitzewitz, Elliot, Haase, Harper, Herzog, Nelson, Nelson, Schuler and ZornMcGraw Hill, 2005
2 Motion An object whose position changes over time. Motion Diagram - shows the positions of a moving object at successive times.
3 Visualizing MotionCoordinate System - shows the location of the zero point (origin) and direction of an object in motion.Arrows can be utilized to show an objects position and distance traveled.
4 Vectors and ScalarsVectors are quantities that have both magnitude (size) and direction.0 15mScalars are quantities that are numbers without direction4C, 5m, 39s, 22m/s
5 Resultant VectorsVector that represents the sum of two or more vectors.Based upon their direction some vectors can be negative.
6 Time Intervals and Displacement Time Interval - equals the final time (tf) minus the initial time (ti)∆ t = tf - tiDisplacement - equals the final position (df) minus the initial position (di)∆ d = df - di
7 Position - Time GraphsBy plotting the time (t) and position (d) data of a particular object a position-time graph can be generated.Remember that d represents that object’s instantaneous position.t d30 055 0
8 Average Velocity v = ∆d / ∆t = df - di / tf - ti Defined as the change in position divided by the time during which the change occurred.v = ∆d / ∆t = df - di / tf - tiAverage velocity is represented by the slope of the line in a position-time graph
9 Speed vs. VelocitySpeed is how fast an object in moving. It is a scalar quantity and therefore can never be negative.Velocity is speed with direction. It is a vector quantity and therefore can be negative.Instantaneous velocity is the speed and direction of an object at a particular instant.
10 Equation of Motion for Average Velocity An object’s position is equal to the average velocity multiplied by time plus the initial position.d = vt + diUse algebra and the equation v = d / t to solve for any of the variables.