1. Speed and Velocity
Chapter 11 section 2 notes

2. Speed
Speed is the ratio of the distance an object moves to the amount of time the object moves.
SI unit for speed is m/s (meters per second)
Always use appropriate units (cm/s, km/hr)

3. Average Speed vs. Instantaneous Speed
Average speed is computed for the entire duration of a trip, and instantaneous speed is measured at a particular instant.
My average speed in my car on the highway is 80 Km/Hr.
My instantaneous speed in my car on the highway at exit 10 is 90 Km/Hr.

4. Formula for Average Speed
Average speed = Total Distance
Total Time OR
v = d t

5. Graphing Motion Motion can be described on a distance- time graph.
The slope of the line is the speed of the motion.
A direct proportional line shows constant speed.

6. Varying Speed

7. Constant Speed

8. Velocity
Velocity is a description of both speed and direction of motion.
Velocity is a vector.
Example: The hippo is moving 90 Km/Hr South

9. Combining Velocities Two or more velocities add by vector addition.
Example:
Velocity of river to riverbank 5 Km/Hr S
Velocity of boat to river 12 Km/Hr S
Added together the velocity of the boat to the riverbank is 17 Km/Hr S