1. One Dimensional Motion
Unit 1
One Dimensional Motion

2. What does the speedometer in my car REALLY measure?
Essential Question 1
What does the speedometer in my car REALLY measure?

3. Is the person in this picture moving?

4. Defining Motion
Reference Point: An object that looks motionless to an observer.
Motion: When an object moves closer or farther away from a reference point.

5. See how reference points work?

6. Space and Time
Physics looks at the world through an objects movement through SPACE and through TIME.

7. Position
Position: The physical location of an object in a frame of reference.

8. Describing Motion

9. Using Math to describe motion
The position and time of an object can be written down in a table or can be put on a scatter plot or line graph.

10. Using Math to describe motion
Position (m)
Time (s) 2 9 5 14 10 20

11. Physics Vocabulary Things you’ll hear the teacher say . . .
Magnitude: The size of the quantity measured. Always positive.
Example: Mr. White’s weight has a magnitude of 180 lbs.

12. Crazy Physics Vocabulary
Things you’ll hear the teacher say . . .
Scalar Measurement: Measureable quantity that just has a magnitude.
Mr. White’s weight is a scalar measurement.

13. Crazy Physics Vocabulary
Things you’ll hear the teacher say . . .
Vector Measurement: A measurable quantity that must also have a direction stated.
Represented by arrows.

14. Vector Example

15. Sounding Smart With Science
Physics uses the term Velocity to describe how quickly something is moving.
Velocity is as vector quantity.
Velocity: Speed with a direction.

16. Velocity Directions with Velocity
Normally going to the right or up is considered the positive directions.

17. Speed vs. Velocity
Speed: The distance something travels in a given amount of time.
How fast something is moving.
How are speed and velocity different?

18. Average vs. Instantaneous Velocity
Instantaneous Speed: The velocity at any given instant in time (like the reading on a speedometer in a car)

19. Average vs. Instantaneous Speed
Average Speed: The average of ALL the instantaneous speeds (Total Distance ÷ Time of Travel)

20. Relative Motion
The same motion can be seen differently depending on where the observer is standing.

21. Adding Velocity
Resultant Velocity: Observed motion when velocities combine.
Velocities in the same direction ADD.
Velocities in OPPOSITE directions SUBTRACT.

22. Relative Velocity
A man on a river bank is watching a fishing boat go up a river. The speedometer on the boat reads 25 mph and the river current is flowing at 4 mph. How fast does the boat appear to be moving to the man on the bank?

23. Average Velocity Equation
𝑣= 𝑑 𝑡
Symbol
Name
Unit v
Average velocity
Distance Unit/ Time Unit & Direction d
Distance
Distance Unit t
Elapsed Time
Time Unit

24. Speed and velocity Practice Problem Set
Example 1
The bearded dragon is the fastest reptile on the planet. It can cover 55 meters in just 5 seconds when it is running at top speed. What is the average top speed of the bearded dragon?

25. Speed and velocity Practice Problem Set
Example 1
The slowest animal ever discovered was a crab found in the Red Sea. It traveled with an average speed of km/year. How long would it take to travel the length of a football field (109.1 meters)? Record your answer in DAYS!

26. Speed and velocity Practice Problem Set
Example 3
Mr. White is driving his car from east to west across the parking lot. If it takes his vehicle 30 seconds to travel 45 meters, what is the average velocity of his car?

27. Does acceleration mean going faster?
Essential Question 2
Does acceleration mean going faster?

28. Acceleration: The rate at which velocity changes.

29. Acceleration in common Terms
Ways velocity changes.
Speed up (Velocity Increases)
Slow Down (Velocity Decreases)
Turn (Change Direction)

30. Acceleration and Direction
Speeding up: Anytime the Velocity & Acceleration Vectors point in the same direction.
Slowing down: Anytime the Velocity & Acceleration Vectors point in the opposite direction.

31. Acceleration Equation
Symbol
Name
Unit a
Acceleration
Distance Unit / Time Unit 2 ∆v
Change in Velocity
Distance Unit / Time Unit v
End Velocity v0
Start Velocity t
Time of Acceleration
Time Unit

32. Distance & Acceleration
Range (Distance) Equation for a constant acceleration.
𝑑= 𝑎∙ 𝑡 2 2
* This equation only works with objects starting or ending at REST!

33. Acceleration Practice Problem Set
Example 1:
Grace is driving her sports car at 30 m/s when a ball rolls out into the street in front of her. Grace slams on the brakes and comes to a stop in 3.0 seconds. What was the acceleration of Grace’s car?

34. Acceleration Practice Problem Set
Example 2:
While driving a car a down a four-lane highway, Eddie comes up behind a slow-moving truck and decides to pass it in the left hand lane. If Eddie can accelerate at m/s2, how long will it take him to increase his car’s velocity by 10 m/s?

35. Acceleration Practice Problem Set
Example 3:
A driver spots a red light up ahead and applies the brakes to make the car slow at a rate of 4 m/s2. If the car travels 18.0 meters while the driver presses the brake pedal, how long did they apply the brakes?

36. Essential question 3
How can the graphing I learned in Algebra help me understand how real things move?

37. Position vs. Time Graphs
Graphs can show how something moves in a single dimension over time.
Moving Man

38. Position vs. Time Graph

39. Position vs. Time Graphs
Describe the motion in each graph? t D t D t D

40. Position vs. Time Graphs
What does the slope of a Position vs. Time graph mathematically represent?

41. Position vs. Time Graphs
Using Graphs to find Instantaneous and Average Velocity

42. Velocity vs. Time Graphs
Graphs can also show how fast something is moving over time.

43. Velocity vs. Time Graphs
How would you describe the motion in each of the graphs below? t v t v t v

44. Velocity vs. Time Graphs
What does the slope of velocity vs time graphs mathematically represent?

45. Making a Graph from Another Graph
Graphing Motion Notes Handout