1. Motion & Speed Unit 1 Lesson 1
Big Idea: Unbalanced forces cause changes in the motion of objects, and these changes can be predicted and describe

2. How are Distance, Time, and Speed Related?
Essential Question
How are Distance, Time, and Speed Related?

3. How can you describe the location of an object?
Position describes the location of an object
Comparisons using known objects or locations often are used to describe position
A reference point is a location to which you compare other locations

4. How can you describe the location of an object?
Describe the positions of the different parts of the zoo.

5. What is Motion? Motion is a change in position over time
Even when motion is not observed directly, starting points and end points can indicate motion has occurred.

6. How is distance measured?
Distance can be measured as a straight line between two positions
Distance can also be measured as the total length of a certain path between two positions
The standard unit of length for distance is the meter (m)

7. How is distance measured?
Which distance is greater: a straight line from A to B or the total length of the path below?

8. What is Speed?
Speed is a measure of how far something moves in a given amount of time.
Speed measures how quickly or slowly an object changes its position.
Fast objects move farther than slower objects in the same amount of time.

9. What is Average Speed?
Average speed is a way to calculate the speed of an object that may not always be moving at a constant speed.
Average speed describes the speed over a stretch of time rather than at any exact moment in time.

10. How is Average Speed Calculated?
Speed can be calculated by dividing the distance an object travels by the time it takes to cover that distance.
speed = distance/time
s = d/t

11. How is Average Speed Calculated?
If two objects travel the same distance, the object that takes less time has the greater speed.
An object with a greater speed travels farther in the same time than an object with a lower speed travels.
The standard unit for speed is meters per second (m/s).

13. Distance = 100m
Time = 13.75s
Average Speed

14. S = d/t
S = 100m / 13.75s

15. S = 100m / 13.75s
S = 7.27m/s
Units is m/s. Unit of speed is distance/time. Units agree
7.27 m/s

17. D = 50m
T = 5s
Average Speed

18. s = d/t
S = 50m / 5s

19. Units is m/s. Unit of speed is distance/time. Units agree

20. What is Velocity?
A vector is a quantity that has both size and direction.
Velocity is speed in a specific direction.
Objects can have the same speed but different velocities because of their direction of travel.

21. What is Velocity?
Average velocity depends on the distance from the starting point to the final point.
Average velocity can be 0 km/h if you travel at a certain speed to one point and then travel back to the starting point.

22. How is Constant Speed Graphed?
Distance-time graphs are used to plot the distance an object travels over time.
The distance of an object away from a reference point is plotted on the y-axis. Time is plotted on the x-axis.
Objects moving at a constant speed make a straight line on the graph.

23. How is Constant Speed Graphed?
The slope, or steepness, of the line is equal to the average speed of the object.
Average speed can be calculated by dividing the change in distance by the change in time for that time interval.
slope = change in y/change in x

25. How are Changing Speeds Graphed?
On a distance-line graph, a change in the slope of a line indicates a change in speed.
If the line gets steeper, the object’s speed has increased.
If the line gets less steep, the object has slowed down.
A flat line indicates zero speed.

26. 0 min
0 cm
2 min
60 cm
3 min
90 cm

27. Distance Time Graphs
The graph shows an object which is not moving (at rest).
The distance stays the same as time goes by because it is not moving.

28. Speed-Time Graphs Velocity-Time Graphsor
Velocity-Time Graphs

29. Distance Time Graphs
The graph shows that the objects distance increases as time passes. The object is moving and so it has velocity.
The straight line shows it is a constant (not changing).

30. Distance Time Graphs
Just like the previous graph, this graph shows an object moving with constant velocity

31. Speed-Time Graphs Velocity-Time Graphsor
Velocity-Time Graphs

32. Distance Time Graphs
The curve in the graph shows that the objects velocity is changing as time passes.
This is acceleration.

33. Distance Time Graphs
In the first part of the graph the object is moving with constant velocity.
In the second part of the graph the object is at rest (not moving).
In the third part the object is again moving with constant velocity.

34. Distance-Time Graphs

35. Velocity-Time Graphs

36. Describe how fast something moves Distance in a time and a direction

37. On Saturday, Ashley rode her bicycle to visit Maria
On Saturday, Ashley rode her bicycle to visit Maria. Maria’s house is directly east of Ashley’s. The graph shows how far Ashley was from her house after each minute of her trip.
1. Ashley rode at a constant speed for the first 4 minutes of her trip. What was her constant speed during the first 4 minutes?
2. What was her average speed for the entire trip?
3. What was her velocity for the entire trip?
4. Ashley stopped to talk with another friend during her trip. How far was she from her house when she stopped? ________________________
5. Ashley’s brother rode beside her for several minutes. During this time, was he moving relative to Ashley?