1. 8.2 Speed Vs Velocity Speed (v):
the distance an objects travels over a given time interval
scalar quantity, SI unit is m/s
Velocity: ( v )
describes the displacement of an object during a given time interval OR how fast an object’s position is changing
velocity can be zero, negative or positive

2. Position Time Graphs & Average Velocity
The slope of a position time graph = average velocity
The rate of change in position for a time interval of an object
Vector quantity, represented as: Vav
Positive Velocity = object is moving away from the origin with uniform speed
Zero Velocity = object is stationary
Negative Velocity = object is
returning to its origin with
uniform motion
Refer to text page 365 for sample calculations and Assign Hw page and page 370 #1-6

3. Velocity 2 People Racing (text pg. 364)
Vector symbols should be there above position
Recall the equation for Average Velocity!
= df – di OR = RISE
tf – ti RUN

4. Position Time Graph of Racers
Solve the following:
1. Who is going faster? How do you know?
Who has the greatest velocity?
See Text page 365 for sample calculations

5. Converting Units Converting between m/s to km/h
Recall: there are 60 s in 1 min and 3600 s in 1 hr
Recall: there are 1000 m in 1 km
Example:
55km x (1000m) x (1 h) = 15 m/s [W]
1 h (1km) (3600s) HW