1. Unit 2 Constant Velocity Motion
Buggy Lab Conclusion
Velocity and instantaneous velocity

2. Objectives
I can…
describe the importance of the slope and y-intercept of a position vs. time graph.
Give a definition for average velocity, average speed, and instantaneous velocity.
Calculate the average velocity of an object from a graph of position vs. time.

3. Lab: Physics Buggy
How did the physics buggy’s distance change over time?
How would you describe the relationship?

4. Lab: Physics Buggy
How did the physics buggy’s distance change over time?
How would you describe the relationship?
How did you determine this from the graph?

5. Lab: Physics Buggy
How did the physics buggy’s distance change over time?
How would you describe the relationship?
How did you determine this from the graph?
What equation did you derive from the data/graph?

6. Position vs. Time
General Equation/Fit =
Position (m)
Time (s)

7. Position vs. Time
General Equation/Fit =
What does the Y-Intercept mean?
Position (m)
Time (s)

8. Position vs. Time
General Equation/Fit =
What does the Y-Intercept mean?
What does the Slope mean?
Position (m)
Time (s)

9. x0 x t t0 A Few more symbols… SYMBOL PRONOUNCIATION MEANING “X naut”
Initial x-position x
“X”
Final x-position t
“T”
Time (as a variable, any time measurement) t0
“T naut”
Initial time (starting time)

10. Y = m x + b

11. Y = m x + b X

12. Y = m x + b
X = t

13. Y = m x + b
X =
T + X0

14. Y = m x + b
X =
T + X0

15. Average Velocity ~
The ratio of the displacement of an object during a particular elapsed time

16. Position vs. Time 2 1
What is the average velocity for: ?
The whole trip? 8 7 B 6 5
Position (m) A C 4 3
Time (s)

17. Position vs. Time 2 1
What is the average velocity for: ?
The whole trip? 8 7 6 5 C
Position (m) A 4 3 B
Time (s)

18. Instantaneous Velocity (or simply velocity)
𝑣= 𝑥 𝑡
Instantaneous Velocity (or simply velocity)
This refers to the specific velocity at specific time
As opposed to an average velocity
Units (m/s)

19. Position vs. Time 2 1 8 7 6 5 C
Position (m) 4 3 B A
Time (s)

20. A
What can you say about A’s
Direction of motion? +/-?
Initial Position? +/-/0?
Velocity? +/-?
Position (m) B
Time (s)

21. A
What can you say about A’s
Direction of motion? +/-?
Initial Position? +/-/0?
Velocity? +/-?
What can you say about B’s
Position (m) B
Time (s)

22. A
What can you say about A’s
Direction of motion? +/-?
Initial Position? +/-/0?
Velocity? +/-?
What can you say about B’s
Which one has a greater velocity?
How do you know?
Position (m) B
Time (s)

23. What can you say about A’s
Direction of motion? +/-?
Initial Position? +/-/0?
Velocity? +/-?
Position (m) A B
Time (s)

24. What can you say about A’s
Direction of motion? +/-?
Initial Position? +/-/0?
Velocity? +/-?
What can you say about B’s
Position (m) A B
Time (s)

25. What can you say about A’s
Direction of motion? +/-?
Initial Position? +/-/0?
Velocity? +/-?
What can you say about B’s
Which one has a greater SPEED?
How do you know?
Position (m) A B
Time (s)

26. Homework Due 8/25 Read and comment on 2 of your classmate’s blogs
Please make the comments meaningful!

27. Y = M X + B
x = v t + x0

28. Y = M X + B
x = v t + x0
If V is constant, than it is equivalent to V0, so the equation becomes:

29. Y = M X + B x = v t + x0 𝑥= 𝑣 0 𝑡+ 𝑥 0 𝑥= 𝑥 0 + 𝑣 0 𝑡
If V is constant, than it is equivalent to V0, so the equation becomes:
Constant Velocity Equation
𝑥= 𝑣 0 𝑡+ 𝑥 0 or
𝑥= 𝑥 0 + 𝑣 0 𝑡