1. Chapter 3 & 4 Velocity and Acceleration Topic 2.1

2. Everything moves... Three ways to describe motion 1. common, ordinary words (sentence) 2. equations (Get ready, here come some more!) and 3. graphs.

3. Mechanics - the study of motion Kinematics - study of how something moves (describe the motion) Dynamics – study of why something moves (explanation of motion)

4. 3.1 How far? How fast? Reference point - choose a zero point Frame of reference ­ directions based on the reference point Position - separation between the reference point and the object

5. Scalar & Vector Quantities Magnitude - the size of the number Example: 1.60x10 -19 ; 55 o ; 512 Scalar - a measurement with only magnitude Example: q = 1.60x10 -19 C; 55 o angle; 512 Hz Vector - a measurement with both magnitude and direction - vectors are drawn as an arrow

6. Distance - separation between two objects (scalar quantity) ( s or d )( meters) Displacement - the change in position (vector quantity) ( s or d )( meters, direction) Examples: walk around the table/track/school

7. Speed - how fast an object moves (scalar quantity) ( v )( m/s or ms -1 ) Velocity - rate of change in position (vector quantity); how fast AND in what direction ( v ) ( m/s, direction or ms -1, direction ) Examples: walk around the table/track/school

8.  = delta = change in Speed Equation:Velocity Equation: v =  distancev =  displacement  t  t v = s/tv = s/t v = d. t

9. Instantaneous velocity (or speed) - the velocity of an object at a single instant in time Examples: Police radar gun, speedometer on your car Average Speed - total distance divided by total time Examples: speed for the whole trip to grandma’s house and back Average Speed Equation: v = total distance = s total total time t total

10. POSITION: reference point = zero Positive (+) = to the right Negative (-) = to the left VELOCITIES: Positive (+) = moving to the right Negative (-) = moving to the left Examples:+ position and + velocity - position and - velocity + position and - velocity - position and + velocity -3 -2 -1 0 1 2 3 4 Positive and Negative Position & Velocities

11. “mks” units ALWAYS! meters-kilograms-seconds Get ready to practice conversions! Homework: Practice Problem page 45 #1-4 page 47 #5-8