Warm Up cm to meters m to km 3. 8,009 g to kg L to mL kg to mg

Introduction to Motion  Objective: Know the difference between distance and displacement and speed and velocity

What is motion?  Motion: change of the position of an object with respect to time Ouch.

 Definition: Total length traveled  What distance did the turtle cover?

 Definition: change in the position of an object from its beginning point  Formula: Δx = x f -x i ΔxΔx xixi xfxf

 Displacement = change in position from start  Distance = total length traveled  What total distance did the turtle cover?  What was his displacement?

Displacement  Positive displacement: moving up or forward  Negative displacement: moving down or backward

Positive or Negative? 2 m 4 m 2 m 4 m

Speed  Definition: rate of change in distance with respect to time  Formula: speed = distance/time

 Definition: rate of change in displacement with respect to time  Formula: v avg = x f – x i = displacement = d t f – t i time t  Units: length/time Average Velocity

 Can be positive or negative  Depends on sign of displacement  Positive velocity = moving forward  Negative velocity = moving backward

Velocity vs. Speed  Velocity is a VECTOR quantity, which means it describes motion with both magnitude and direction  Rate of change of DISPLACEMENT with respect to time  Speed is a SCALAR quantity, which means it has no direction, only magnitude  Rate of change of DISTANCE with respect to time  Video (Vector) Video (Vector)

The GUESS Method  During football practice, Martin and Johnv run 2.7 miles eastward in 25 minutes. How fast were they running? G iven U nknown E quation S ubstitute S olve 2.7 miles = d, 25 minutes = t velocity v = d/t v = 2.7 miles/25 minutes v = miles/min eastward

Homework  Textbook Problems p. 62 #2, 5, 6, 26-31

Lab/Activity  Intro to Motion Detectors

Exit Question (use GUESS)  A turtle walks 2.0 meters forward in 10 minutes. What is the Turtle’s velocity?  G  U  E  S