1. Motion
Speeding Forward

2. Motion
Motion: A change in position, measured by distance & time.

3. Reference Point
A reference point is a place or object used for comparison to determine if something is in motion.
An object is in motion if it changes position relative to a reference point
Some point must be considered as nonmoving.
The Earth is the most common reference point.

4. Relative Motion All Motion is Relative.
Whether or not an object is in motion depends on the reference point.

7. Speed Speed is the distance the object travels per unit of time.
Speed is a type of rate
Speed only gives distance & time
Ex. 60 km/hour

8. Calculating Speed
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
Distance= Time times Speed
Time= Distance/Speed

9. Average Speed
Speed of most moving objects is not constant. Average Speed is total distance (d) traveled divided by the total time (t).

10. Average Speed Example
Total distance = 36 miles + 24 miles = 60 miles Total time = 3 hours + 1 hour = 4 hours Average speed (v) = d = 60mi t 4 = 15 mph

11. Velocity
Velocity is speed in a given direction. Velocity gives distance, time and direction of travel. Ex. 50 miles/hour to the west Changes in velocity may be due to changes in speed, changes in direction or both.

12. Toy Soldier March
Distance In Cm
# of Turns (independent var.)

13. Wind up Toy Data Table Trial Number of Turns Distance Traveled Trial 1
Trial 2
Trial 3

14. Speed of Battery Operated Car1 2 3 4 5 6 7
Total Distance
Time
Trial #1
Time Trial #2
Time Trial #3
Avg time
Speed Fraction
Average speed for each 100 cm
(Cm)
(S)
(Cm/s)
0.00
0/00
----
100
200
300
400
500
600

15. Battery Powered Car Lab
Distance vs. Time Graph
Distance in Cm
Time in seconds

18. Changing Velocity
Acceleration is the rate at which velocity changes with time.
In science, acceleration refers to increasing speed, decreasing speed or changing direction.
Like displacement and velocity, acceleration is a vector with a magnitude and a direction.

19. Increasing Speed
Whenever an object’s speed increases, the object accelerates.

20. Decreasing Speed
Just as objects can speed up, they also slow down, this is called deceleration or negative acceleration.

21. Calculating Acceleration
To determine the acceleration of an object, you must calculate its change in velocity per unit of time. Acceleration = Final velocity – Initial velocity Time

22. Distance – Versus – Time Graph
You can also show the motion of an accelerating object with a distance – versus – time graph.

23. Accelerated Motion Matchbox Car LabDi
stance
In cm
Time in Seconds

24. Students
Car
Trial
Distance (m)
Time (sec)
Speed (m/s) 1
0.6 2 3
Average
1.2
1.8
2.4
1.20
0.5
1.35
1.27
1.70
1.65
1.72
1.69
1.83
1.85
1.84
2.00
2.10
2.05

25. References
motion-and-energy.php