Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. The kinematics of motion in one dimension Problem-solving strategies Motion Diagrams and Pictorial Diagrams Chapter 2 Motion in One Dimension Topics: Sample question: Horses can run much much faster than humans, but if the length of the course is right, a human can beat a horse in a race. When, and why, can a man outrun a horse? Slide 2-1

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. From this class: In Chapter 1 you began studying motion in one dimension. We continue the development of the concepts in this chapter. In Chapter 1 you saw how to represent motion using a motion diagram. In this chapter we will look at other ways to represent motion. In Chapter 3, you learned how to find  v and acceleration vectors graphically From previous classes: We will use graphical representations of motion extensively in this chapter. You should have learned how to draw, interpret, and work with graphs in previous courses. Slide 2-2 Looking Back: What You Already Know

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 3-28 The diagram below shows two successive positions of a particle; it’s a segment of a full motion diagram. Which of the acceleration vectors best represents the acceleration between v i and v f ?  

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 3-29 The diagram below shows two successive positions of a particle; it’s a segment of a full motion diagram. Which of the acceleration vectors best represents the acceleration between v i and v f ?  Answer 

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 1-7 Can you move? Fill in the tables for these motion events by indicating whether or not a motion event is possible. If it is, give an example. If not, explain why not. DisplacementFinal PositionPossible?Example/Explanation 00 0Not 0 0 Average SpeedAverage Velocity Possible?Example/Explanation 00 0Not 0 0

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Reading Quiz 1.The slope at a point on a position-versus-time graph of an object is A.the object’s speed at that point. B.the object’s average velocity at that point. C.the object’s instantaneous velocity at that point. D.the object’s acceleration at that point. E.the distance traveled by the object to that point. Slide 2-3

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. 1.The slope at a point on a position-versus-time graph of an object is C.the object’s instantaneous velocity at that point. Slide 2-4 Answer

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 1-7 Problem Solving Strategy (PSS) On problems, it is important to show how you reasoned from the information given in the problem and key physics ideas to your final answer. The correct final answer with units is only worth 1-3 points. The remainder of the points are given for the quality of your solution. You are expected to include the following to receive full credit: Prepare Identify the Physics: State explicitly which physics principle apply to the problem situation and that you will use to solve the problem Drawing a Picture: Draw at least one picture to visualize the physics of the problem and define your variables and constants. For motion problems this could be a motion diagram, motion graph, or pictorial diagram (Friday) Collecting Necessary Information: State all the information given in the problem with correct units. Include preliminary calculations such as unit conversions Assume/Observe: State assumptions or observations that would be useful Solve Start with key equation(s) in symbol form Solve for the unknown quantity in symbols before numeric calculations Then substitute numbers with units and calculate the numeric answer Assess Check to see if your answer is reasonable Does it answer the question that was asked Does it have the right units? Be prepared to make reasonable estimations and state your assumptions when solving problems. Be aware of significant digits in your answers. (Keep lots of digits until the final calculation, then round to the appropriate precision. For intermediate steps, remember to keep one extra siginificant digit

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Solving Problems - Prepare (also identify key physics) Slide 2-10

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 2-11 Solving Problems (continued)

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Nine years ago, the eye of hurricane Floyd passed over Grand Bahama Island heading due west at a speed of 15 km/hr. Four hours later, the course of hurricane Floyd shifted to North-West towards the Florida coast and its speed increased to 20.0 km/hr. Floyd continued on this course at this speed for three hours before turning due north again. A.How far from Grand Bahama was hurricane Floyd 6 hours after it passes over the island? B.What was Floyd's average speed during this time? C.What was Floyd's average velocity during this time? D.Sketch a vector representing hurricane Floyd's average acceleration during this time? Try to work in symbols as much as you can Solution using Problem Solving Strategy (PSS Solution) Solution Slide 2-4 Problem Solving Example: Where's the Storm?

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Pictorial Diagrams Slide 2-12

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 2-4 Pictorial Diagram Example 1

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 2-4 Pictorial Diagram Example 2

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Representations Slide 2-9 Motion diagram (student walking to school) Table of data Graph

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Interpreting Graphs Slide 2-12