1. Speed: measure of the distance an object travels per unit of time Units: m/s, km/h, mph
Constant Speed: rate of change of position in which the same distance is traveled each second (with changing speed the rate of change is not the same for each second)
Instantaneous speed: when speed is not constant it is the speed at a specific instant in time
Average Speed: total distance traveled divided by the total time taken to travel that distance
Calculate:
Speed = Distance / time

2. The steeper the slope, the faster the speed
Distance – Time Graphs
Constant At rest Slowing down Speeding up
The steeper the slope, the faster the speed

3. Calculating Average Speed from a graph (p154)
Choose 1 point and record the coordinates (x1, y1)
Choose a second point and record the coordinates (x2, y2)
Find the difference in the times (x2- x1)
Find the difference in the distances (y2- y1)
Divide the difference in the distance by the difference in the time (S=d/t)

4. Velocity: Speed and DIRECTION
Velocity changes when:
Speed changes
Direction changes
Both speed and direction change
Velocity is represented by arrows:
length of the arrow shows the speed (faster speed = longer arrow)
Arrows point in the direction of the movement