1. Motion, Speed, & Velocity
Chapter 10
Motion, Speed, & Velocity

2. OBJECTIVES
Explain the relationship between motion and a frame of reference.
Distinguish between distance and displacement.
Relate speed to distance and time.
Distinguish between speed and velocity.
Solve problems involving time, distance, speed, and velocity.

3. While watching the following clip, think of how you might describe the movement/motion of what you see…

5. MOTION: an object’s change in position relative to a reference point

7. Frame of Reference

8. A B DISTANCE: measures the path taken Can be straight or curved
Total amount covered
SI units = meters (m)
Example: 5 meters (m) A B

9. A B DISPLACEMENT: the change in the position of an object
Always indicates a direction
Always in a straight line
Measures only from the starting point to the ending point
Example: 5 meters to the east A B

10. Which line is displacement?
Which line is distance?
END
START

11. Distance or displacement?

12. 10 miles

13. Always a straight line

14. Can be a straight line or curved line

15. 20 miles east

16. Always shows direction

17. Total amount covered

18. Think!
Give one example of distance and one example of displacement (include units):
Distance:
Displacement:

19. Speed = Distance v = d Time t
SPEED: distance traveled divided by the time during which motion occurred.
Speed = Distance v = d
Time t
Need to measure Length & Time
Can’t be negative
SI unit: meters/seconds (m/s)

20. 3 TYPES OF SPEED CONSTANT (speed not changing)
Example: using cruise control
AVERAGE (Total distance divided by total time)
Example: the entire trip speed
INSTANTANEOUS (speed at any given moment)
Example: using a speedometer/radar gun
Main Street PP
Second Street
Front Street W
Route 33

21. VELOCITY: the speed of an object in a particular direction
Must include the direction object travels
Example: East, West, North, South, Up, Down, etc.
Speed = Distance v = d
Time t
Can be negative d v t
v = d/t
d = v * t
t = d/v

22. RESULTANT VELOCITY: Adding or subtracting velocities
Example: Boat moving on flowing river, Person walking on airplane, etc.
7 m/s East
3 m/s East
10 m/s East
7 m/s East
3 m/s West
4 m/s East

24. Speed or velocity?

25. Can’t be negative

26. Includes Direction

27. Can be negative

28. M/S

29. Think!
How are velocity and speed the same? How are they different (include units)?

30. Velocity Practice Problem #1
A car heading east travels 180 kilometers (km) in 2 hours. How fast is the car traveling?
d =
t =
v = d v t

31. Velocity Practice Problem #2
A hockey player skating at 5 m/s during practice, skates for 10,000 seconds. How far did he skate?
d =
t =
v = d v t

32. Velocity Practice Problem #3
When flying their 500 mile journey for the winter, geese fly at a speed of 25 mph. How long does it take the geese to travel south?
d =
t =
v = d v t

33. Comparisons Distance & Speed Displacement & Velocity
________Direction (Scalar)
___________negative
Displacement & Velocity
________Direction (Vector)
___________negative NO
HAVE
CAN’T BE
CAN BE

34. GRAPHING VELOCITY/SPEED x-axis = time
y-axis = displacement (or distance)
slope = velocity/speed
y-axis
faster
slope = velocity = d2 – d1
t2 – t1
d = displacement
t = time
slope = velocity
Example for Top Line
slope = velocity = 100m – 0m
60s – 0s
= 100m
60s
= 1.67m/s
slower
starting point
x-axis

35. COMMON DISPLACEMENT/TIME GRAPH TRENDS
Straight diagonal line up = constant speed away from start
Straight diagonal line down = constant speed toward start
Straight horizontal line = speed equals zero (stopped)
Curved up = acceleration
Sloped down = deceleration

36. Graphs for 2 Runners
Which graph shows one runner starting 10 yards in front of the other runner?
Which graph shows one runner ending 40 yards away from the starting point?
Which graph shows both runners ending at the same place at the same time?

37. Graphs for 2 Runners
Which graph shows both runners moving at the same velocity?
Which graph shows one runner passing the other runner?
Which graph shows that one runner ran a total of 30 yards while the other runner ran a total of 10 yards?

38. Exit Ticket: Motion- Speed/ Velocity #17-20

39. Exit Ticket
17. Which of the following DOES NOT indicate velocity?
20 km/h SE
It is 50 KM from Logan
45 km/h toward the center of town along Main St
Driving 100 km/h going from Indiana to Ohio

40. Exit Ticket
18. Which of the following DOES NOT require a direction?
Speed
Velocity
Displacement
Acceleration

41. Exit Ticket
19. To measure velocity you have to have the &
the of an object.
speed, velocity
Speed, direction
Location, direction
distance, time

42. Exit Ticket
20. Which is an example of displacement?
50 km/h
50 km
50 km south
50 km/h south