Lecture Presentation Chapter 1 Representing Motion
Chapter Assignment # s 65, 67, & RT-2 Chapter Goal: To introduce the fundamental concepts of motion and to review related basic mathematical principles. Slide 1-2
Reading Question 1.1 What is the difference between speed and velocity? A. Speed is an average quantity while velocity is not. B. Velocity contains information about the direction of motion while speed does not. C. Speed is measured in mph, while velocity is measured in m/s. D. The concept of speed applies only to objects that are neither speeding up nor slowing down, while velocity applies to every kind of motion. E. Speed is used to measure how fast an object is moving in a straight line, while velocity is used for objects moving along curved paths. Slide 1-3
Reading Question 1.1 What is the difference between speed and velocity? A. Speed is an average quantity while velocity is not. B. Velocity contains information about the direction of motion while speed does not. C. Speed is measured in mph, while velocity is measured in m/s. D. The concept of speed applies only to objects that are neither speeding up nor slowing down, while velocity applies to every kind of motion. E. Speed is used to measure how fast an object is moving in a straight line, while velocity is used for objects moving along curved paths. Slide 1-4
Reading Question 1.2 The quantity 2.67 10 3 has how many significant figures? A. 1 B. 2 C. 3 D. 4 E. 5 Slide 1-5
Reading Question 1.2 The quantity 2.67 10 3 has how many significant figures? A. 1 B. 2 C. 3 D. 4 E. 5 Slide 1-6
Reading Question 1.3 The correct SI units for distance and mass are A. Feet, pounds. B. Centimeters, grams. C. Meters, grams. D. Meters, kilograms. Slide 1-7
Reading Question 1.3 The correct SI units for distance and mass are A. Feet, pounds. B. Centimeters, grams. C. Meters, grams. D. Meters, kilograms. Slide 1-8
Reading Question 1.4 If Sam walks 100 m to the right, then 200 m to the left, his net displacement vector A. Points to the right. B. Points to the left. C. Has zero length. D. Cannot tell without more information. Slide 1-9
Reading Question 1.4 If Sam walks 100 m to the right, then 200 m to the left, his net displacement vector A. Points to the right. B. Points to the left. C. Has zero length. D. Cannot tell without more information. Slide 1-10
Reading Question 1.5 Velocity vectors point A. In the same direction as displacement vectors. B. In the opposite direction as displacement vectors. C. Perpendicular to displacement vectors. D. In the same direction as acceleration vectors. E. Velocity is not represented by a vector. Slide 1-11
Reading Question 1.5 Velocity vectors point A. In the same direction as displacement vectors. B. In the opposite direction as displacement vectors. C. Perpendicular to displacement vectors. D. In the same direction as acceleration vectors. E. Velocity is not represented by a vector. Slide 1-12
Section 1.1 Motion: A First Look
Types of Motion Motion is the change of an object s position or orientation with time. The path along which an object moves is called the object s trajectory. Slide 1-14
Making a Motion Diagram Constant Speed Speeding Up Slowing Down Slide 1-15
Making a Motion Diagram Motion in 2 Dimensions Changes in Speed & Direction. Slide 1-16
QuickCheck 1.1 Car A Car B Motion diagrams are made of two cars. Both have the same time interval between photos. Which car, A or B, is going slower? Slide 1-17
QuickCheck 1.1 Car A Car B Motion diagrams are made of two cars. Both have the same time interval between photos. Which car, A or B, is going slower? Slide 1-18
The Particle Model A simplification Treat a moving object as if its mass were at a single point Slide 1-19
QuickCheck 1.2 Two runners jog along a track. The positions are shown at 1 s intervals. Which runner is moving faster? Slide 1-20
QuickCheck 1.2 Two runners jog along a track. The positions are shown at 1 s intervals. Which runner is moving faster? A Slide 1-21
QuickCheck 1.3 Two runners jog along a track. The times at each position are shown. Which runner is moving faster? A. Runner A B. Runner B C. Both runners are moving at the same speed. Slide 1-22
QuickCheck 1.3 Two runners jog along a track. The times at each position are shown. Which runner is moving faster? A. Runner A B. Runner B C. Both runners are moving at the same speed. Slide 1-23
Practice Slide 1-24
Section 1.2 Position and Time: Putting Numbers on Nature Section 1.3 Velocity
Position and Coordinate Systems Position needs Origin a reference point Distance from the origin Direction from the origin Slide 1-26
Position and Coordinate Systems Coordinate System an origin an axis both positive and negative directions Slide 1-27
Position and Coordinate Systems The symbol that represents a position along an axis is called a coordinate. Slide 1-28
Time For a complete motion diagram we need to label each frame with its corresponding time (symbol t) as read off a clock. Slide 1-29
Changes in Position and Displacement A change of position is called a displacement. Displacement is the difference between a final position and an initial position: Slide 1-30
Change in Time In order to quantify motion, we ll need to consider changes in time, which we call time intervals. Δt is always positive. Slide 1-31
QuickCheck 1.4 Maria is at position x = 23 m. She then undergoes a displacement x = 50 m. What is her final position? A. 27 m B. 50 m C. 23 m D. 73 m Slide 1-32
QuickCheck 1.4 Maria is at position x = 23 m. She then undergoes a displacement x = 50 m. What is her final position? A. 27 m B. 50 m C. 23 m D. 73 m Slide 1-33
QuickCheck 1.5 An ant zig-zags back and forth on a picnic table as shown. The ant s distance traveled and displacement are A. 50 cm and 50 cm B. 30 cm and 50 cm C. 50 cm and 30 cm D. 50 cm and 50 cm E. 50 cm and 30 cm Slide 1-34
QuickCheck 1.5 An ant zig-zags back and forth on a picnic table as shown. The ant s distance traveled and displacement are A. 50 cm and 50 cm B. 30 cm and 50 cm C. 50 cm and 30 cm D. 50 cm and 50 cm E. 50 cm and 30 cm Slide 1-35
Velocity and Speed Motion at a constant speed in a straight line is called uniform motion. Slide 1-36
Velocity and Speed Speed measures only how fast an object moves, but velocity tells us both an object s speed and its direction. Slide 1-37
Practice Slide 1-38
Section 1.4 A Sense of Scale: Significant Figures, Scientific Notation, and Units
Scientific Notation What is the importance of Scientific Notation? Efficiency Number of Sig Figs Tactics Box 1.2: Page 13 Also USE YOUR CALCULATOR Slide 1-40
Significant Figures Precision Slide 1-41
Significant Figures Slide 1-42
Significant Figures What is the importance of Significant Figures? Digits that are reliably known. Tactics Box 1.1: Page 12 Multiplication and Division Addition and Subtraction Slide 1-43
QuickCheck 1.7 Rank in order, from the most to the least, the number of significant figures in the following numbers. For example, if b has more than c, c has the same number as a, and a has more than d, you would give your answer as b > c = a > d. a. 8200 b. 0.0052 c. 0.430 d. 4.321 10 10 A. d > c > b = a B. a = b = d > c C. b = d > c > a D. d > c > a > b E. a = d > c > b Slide 1-44
QuickCheck 1.7 Rank in order, from the most to the least, the number of significant figures in the following numbers. For example, if b has more than c, c has the same number as a, and a has more than d, you would give your answer as b > c = a > d. a. 8200 b. 0.0052 c. 0.430 d. 4.321 10 10 2 2 3 4 A. d > c > b = a B. a = b = d > c C. b = d > c > a D. d > c > a > b E. a = d > c > b Slide 1-45
Units le Système International d Unités or SI Units. Slide 1-46
Estimation A one-significant-figure estimate or calculation is called an order-of-magnitude estimate. Slide 1-47
Practice Slide 1-48
More Practice Slide 1-49
Labs: What is expected?
Lab Write-Ups Will Include Your Name 1pt Your Partner s Name(s) 1pt Title 1pt Background 2pts Materials 2pts Procedure 2pts Data 2pts Calculations 2pts Conclusions 2 pts Slide 1-51
Cover Page Your Name First Name First Last Name Last Partner s Name(s) List in Alpha Order by Last Name Title Should not include the word Lab Slide 1-52
Basic Information Background Written in Essay Form Gives the reader an understanding of the basic physics needed to follow your work Materials Bullet List Everything you used to complete the lab Procedure Numbered List Describing all steps taken to complete the lab Slide 1-53
The Heart of the Lab Data Charts Calculated and Measured Information Graphs Pictures Calculations By hand but scanned Givens, Formula, Sub w/units, Final Ans. w/units Conclusions Written in Essay Form Uses evidence from and refers back to data/procedures/calculations Cite Specific Examples and Numbers Slide 1-54
Other Works Cited Page Should be in it but we are leaving it out Do NOT Plagiarize Text Book Internet Partners Groups Can Have Identical Titles Materials Procedure Data Slide 1-55
Lab
Calculate the Height of Calhoun High School 1 Protractor per Group 1 Meter Stick per Group 1 30m Measuring Tape per Class Clip Boards Pen Paper Calculator Calhoun High School Slide 1-57
Section 1.5 Vectors and Motion: A First Look
Scalars and Vectors A scalar quantity is a number with a unit (size) A vector quantity is a quantity that has both a size and a direction We graphically represent a vector as an arrow. The size or length of a vector is called its magnitude. Slide 1-59
Displacement Vectors An object s displacement vector is drawn, in a straight line, from the object s initial position to its final position, regardless of the actual path followed between these two points. It has length (magnitude) and direction Slide 1-60
Vector Addition The net displacement for a trip with two legs is the sum of the two displacements that made it up. Text: p. 17 Slide 1-61
QuickCheck 1.6 Given vectors and, what is? Slide 1-62
QuickCheck 1.6 Given vectors and, what is? A. Slide 1-63
Velocity Vectors The motion diagram for a car starting from rest Slide 1-64
Practice Slide 1-65
More Practice Slide 1-66