1. How do you calculate speed? How do you describe velocity?
Chapter 8 Lesson 4
Speed & Velocity
How do you calculate speed?
How do you describe velocity?
How do you graph motion?

3. The distance an object travels/moves in a unit of time; a type of “rate”.
Speed

4. To calculate the speed of an object, divide the distance the object travels by the amount of time it takes to travel that distance:
Speed= Distance Time
The Speed Equation

6. Divide total distance traveled by the total time:
Average Speed
Divide total distance traveled by the total time:
Distance ÷ Time

7. AVERAGE SPEED
Use the data in the boxes below to calculate each triathlete’s average speed during the swimming and biking legs of the race (p. 308)

8. 3.0 km km km = 65.0 km
0.8 h h h = 5.0 h
65.0 km/5.0 h = 13 km/h
1.0 h h h = 4.5 h
65.0 km/4.5 h = 14.4 km/h
Triathlete B

9. the speed of an object at a given time
Instantaneous Speed
the speed of an object at a given time

10. divide the distance by the time.
instantaneous

11. An object’s speed & direction
Velocity
An object’s speed & direction
An error in determining velocity, either in speed or in direction, could lead to a collision

12. The pilots need to
control both speed
and direction, or
velocity, to fly in
formation.

13. velocity

14. 1,000 m west and 600 m south
Total distance = 1600m (1, m)
Total time = 300 s (5 min x 60 s)
Average speed = 5.3 m/s (1600/300 s)
speed and direction of
the object’s motion.
…by the distance it travels
and its average speed
and direction.

15. Plot distance verses time
How Do You Graph Motion?
With a line graph
Plot distance verses time

16. Distance verse time graph:
X-axis-horizontal line/independent variable
Always has time plotted on it!
Y axis- vertical line/ dependent variable

17. The steepness of a line on a line graph
Slope
The steepness of a line on a line graph

18. What does a slope show? The rate of change in speed
The steeper the slope is, the greater the speed

19. slope No; the object would have to cover distance in no time.
1 min
0 m/min
200 m
1 min
200 m/min
150 m
1 min
150 m/min
slope
No; the object would
have to cover distance
in no time.
Slope = 900 m/3 min
= 300 m/min

20. Time is on the x axis & distance is on the y axis
Speed= Distance ÷
Time
How do you calculate speed?
Review
2. How do you describe velocity?
With speed & direction
Time is on the x axis & distance is on the y axis
3. How do you graph motion?