1. Interpreting Motion Graphs

2. Motion
A change in position measured by distance and time.

3. Speed
The rate at which an object moves.

4. Velocity
The speed and direction of a moving object.

5. Acceleration
The rate, speed, or direction changes.

6. Reference Point
A place or object used for comparison to determine if something is in motion.
So…a fly is sitting on the shoulder of a man sitting in a car. The car is traveling at 60 mph. Is the fly in motion?

7. Key Points A straight line shows constant speed.
A curved line shows average speed.
A horizontal line shows no motion on a distance- time graph, and constant, steady speed on a speed-time graph.
Time is on the x-axis, distance (OR SPEED) is on the y-axis.
The steeper the graph, the faster the motion.

8. Time is always on the x-axis. Distance is always on the y-axis.
Distance-Time Graphs
Time is always on the x-axis. Distance is always on the y-axis.

9. Time is always on the x-axis. Speed is always on the y-axis.
Speed-Time Graphs
Time is always on the x-axis. Speed is always on the y-axis.
Speed

10. Distance-Time: NO MOTION
Time is increasing, but distance does NOT change. It is NOT MOVING…NO MOTION…AT REST.

11. Speed-Time: CONSTANT SPEED
Time is increasing, but speed does NOT change. It is moving at a constant speed. **Like cruise control**
Speed

12. Distance-Time: CONSTANT SPEED
Time and distance are INCREASING at a constant rate. This graph shows CONSTANT SPEED.

13. Speed-Time: CONSTANT SPEED
Time and speed are INCREASING at a constant rate. This graph shows CONSTANT SPEED.
Speed

14. Distance-Time: CONSTANT SPEED
This graph shows a change in direction (meaning the object is headed back to the starting point). This graph also shows CONSTANT SPEED.

15. Speed-Time: CONSTANT SPEED
This graph shows time is INCREASING while speed is DECREASING at a constant rate. This graph also shows CONSTANT SPEED.
Speed

16. Distance-Time: FASTER SPEED
A steeper line shows greater distance traveled in a given time. The STEEPER THE LINE, the HIGHER THE SPEED.

17. Speed-Time: FASTER SPEED
A steeper line shows speed increasing in shorter amount of time. The STEEPER THE LINE, the HIGHER THE SPEED.
Speed

18. Distance-Time: ACCELERATION
In a given time, the distance the object moves is getting larger, it is ACCELERATING. The curve upward shows an INCREASE in SPEED.

19. Speed-Time: ACCELERATION
In a given time, the speed at which the object is travelling is increasing, it is ACCELERATING. The curve upward shows an INCREASE in SPEED.
Then, the speed increases rapidly
Initially, the object is traveling at a slower speed
Speed

20. Distance-Time: DECELERATION
This graph is the same as above, but the curve downward shows DECELERATION or a DECREASE IN SPEED.

21. Speed-Time: DECELERATION
In a given time, the speed at which the object is travelling is decreasing, it is DECELERATING. The curve downward shows a DECREASE IN SPEED.
The speed rapidly declines and the object slows down
Speed
Initially, the object is traveling at a very fast speed.

22. Putting it all together

23. Putting it all together
Speed
increasing speed at a constant rate
constant speed
decreasing speed at a constant rate