1. Speed and Velocity
11.2 Page

2. SPEED
Speed is the RATIO of the distance an object moves over the amount of time the object moves
SI Units = Meters per second (m/s)

3. Average Speed
Average speed is computed for the entire duration of a trip, and instantaneous speed is measured at a particular instant.
Average speed: Driving to the mall 25 mi/hr, hit stop lights, freeway 55 mi/hr, off ramp 25 mi/hr, stop lights, slow in the parking lot.
Instantaneous speed: When police officers tag cars for speeding they are measuring the speed at that moment in time

4. Average Speed Average Speed = total distance total time v = d t
Pg 333 Example:
You travel 35 kilometers in 0.4 hours and then you travel 53 kilometers in 0.6 hours. What is your average speed for the entire trip?
Total distance  35 km + 53 km  88km
Total time h h h
 88 km  88 km/hr
1.0 h or

5. Instantaneous Speed
The rate at which an object is moving at a given moment in time
When police officers tag cars for speeding they are measuring the speed at that moment in time

6. Graphing Motion
Slope of a line on a distance-time graph is the object’s speed

7. Distance-Time Graph Faster the speed -- the steeper the line
Curved line -- the speed is increasing or decreasing
Straight line -- constant speed

8. Velocity The speed and direction in which an object is moving
Speed in a given direction
Description of Speed AND direction of motion

9. Combining Velocities
Combine velocities using vector addition. Two or more velocities add by vector addition
Add velocities in the same direction
Subtract velocities in opposite directions
Current 3 m/s 
Swimmer 2 m/s
Total velocity of swimmer = 5 m/s

10. Combining velocities that are not in a straight line
You can determine the resultant velocity of the boat relative to the riverbank by measuring from the tail of one vector to the head of the other

11. QUESTOINS?? Pg 333 - Extra practice = answer the practice problems
Homework: Worksheet Speed and Velocity