1. I can . . .
explain the difference between average speed and instantaneous speed.
explain the difference between speed and velocity.
explain the difference between velocity and acceleration.
explain the meaning of the slope of a graph involving position, velocity, or acceleration with respect to time.
recognize the appropriate units of each concept.

2. Rate is defined as: Examples: Any Quantity divided by Time
Inches of Rain per Hour
Pizzas per Day
Vibrations per Second

3. relative to something else.
Speed is the RATE
at which your
position changes
relative to something else.

4. Moving relative to what?
LINEAR MOTION
Is this car “moving”?
Moving relative to what?

8. Relative Motion 15 knot wind 15 knot sailboat
What is the speed of the wind relative to the boat?

9. Change in Position Time
Average Speed ≡
∆ x t ≡ ÷

10. Distance Time
Average Speed = ÷

11. Units
miles hour
meters second
inches minute
centimeters year

12. Fundamental Units
M.K.S. System
Meters
Kilograms
Seconds

13. All Possible Units American Metric (SI) M.K.S
Feet Yards
Inches Miles Ounces Gallons Pounds Cups
Teaspoons
Centimeter Millimeter Liter
Milliliter Grams
Hours Minutes
Days
Years
Seconds
M.K.S
Meters Kilograms
Thingamajigs Two shakes of a lambs tail Jiffy Bushel

14. 328 ft s =
16.7 ft s
1 mi 5280 ft
3600 s 1 hr
11.4 mi hr

16. Average Speed ≡
∆ Position ∆ Time
Rise Run =
∆ Y ∆ X
Slope ≡

17. Average Speed ≡
Slope ≡
Rise Run =
∆ Y ∆ X
∆ Position ∆ Time

18. Circumference = 2·π·6,378 km = 40,070 km
40º
6,378 km
Circumference = 2·π·6,378 km = 40,070 km
Speed =
40,070 km 24 hr
= 1670 km/hr

19. Circumference = 2·π·149,500,000 = 939,336,203 km
939,336,203 km 365 days
939,336, · 24
1 day 24 hr = =
107,000 km/hr

20. 246,000,000,000,000 km
223,000 years
6,930,000,000 km/hr
220 km/sec

21. If a car has an average speed of 48
If a car has an average speed of 48.3 meters per second, how long will it take to travel a distance of 6,740 m?
V =
d t

22. If a car has an average speed of 48
If a car has an average speed of 48.3 meters per second, how long will it take to travel a distance of 6,740 m?
V =
d t
Write down the EQUATION!
48.3 =
6740 t t
Plug numbers into the EQUATION! t
48.3
48.3
Carefully use ALGEBRA to solve the equation.
t =
t = 1.40 x 102

23. Your speed at any given moment
Instantaneous Speed
Your speed at any given moment

24. Average speed from 3 to 8 seconds Average speed from 3 to 6 seconds
270 meters
Average speed from 3 to 4 seconds
Instantaneous speed at 3 seconds

25. Is driving 1100 miles in 13 hours reasonable?
Distance Time
Average Speed =
1100 miles 13 hours = 85
mi hr =

26. NO! 85 mph AVERAGE 50 + 100 + 0 + 67 + 125 + 67 6 68 mph 125 mph
68 mph

27. “B” Which ball gets to the finish line first?
It has a higher average speed!

28. Velocity ≡ Speed in a Given DIRECTION
Speed vs. Velocity
Velocity ≡ Speed in a Given DIRECTION
SPEED: 55
miles hour
VELOCITY: East
miles hour

29. 180 mph
180 mph

30. 180 mph
Same SPEED
180 mph
Different VELOCITIES

31. Change in Velocity Time≡
Acceleration
∆ V t ≡ ÷ 50
miles hour 70
10 sec

32. Acceleration ≡ = = = 2 = 2 ∆ Velocity Time Vf – V0 t 70 – 50 10 sec
mi hr
= 2
mi hr sec
mi hr
1 sec 1
= 2
mi hr ·sec

33. Acceleration = 10 mi/hr/s Acceleration = 5 mi/hr/s? ?
Acceleration = 10 mi/hr/s
Acceleration = 5 mi/hr/s 10 20 30 40 50 60 70 80 90
100
110
120
130 10 20 30 40 50 60 70 80 90
100
110
120
130
miles per hour
miles per hour 3 4 5 1 2 10 9 8 7 6 6 3 2 1 9 4 10 5 8 7
Time = s

34. Name THREE controls on car that cause the car to ACCELERATE.
Acceleration
Δvelocity Time ≡
Name THREE controls on car that cause the car to ACCELERATE.
Gas (accelerator)
Brake
Steering Wheel

35. Acceleration is a CHANGE in VELOCITY over time.
You can change your velocity by EITHER changing your SPEED or your DIRECTION.
70 mph
70 mph

37. Acceleration ≡ ∆ Velocity ∆ Time Rise Run
Average Acceleration
Acceleration ≡
∆ Velocity ∆ Time
Rise Run =
∆ Y ∆ X
Slope ≡

38. Acceleration

42. Field Trip!
5 ft
4 ft
3 ft
2 ft
1 ft

43. Change in Velocity Time≡
Acceleration
∆ v t
a =
m s s
a = 5
Example:
m s
1 s 1
m s·s
a = 5
m s2
a = 5

44. What is the instantaneous velocity after 30 seconds?
m s2
Acceleration = 5
EVERY second the velocity changes by 5 m/s
What is the instantaneous velocity after 30 seconds? 35 7 30 6 25 5 20 4 15 3 10 2 1
Instantaneous Velocity (m/s)
Time (seconds)
Vf = a·t
Vf = 5·0 = 0
Vf = 5·1 = 5
Vf = 5·2 = 10
Vf = 5·3 = 15
Vf = 5·4 = 20
Vf = 5·5 = 25
Vf = 5·6 = 30
Vf = 5·7 = 35
Vf = 5·30 = 150

45. vx = +100 m/s + (5 m/s2)(30 s)
= 250 m/s
vx = +100 m/s + (- 5 m/s2)(30 s)
= -50 m/s
vx = -100 m/s + (- 5 m/s2)(30 s)
= -250 m/s

46. I can . . .
explain the difference between average speed and instantaneous speed.
explain the difference between speed and velocity.
explain the difference between velocity and acceleration.
explain the meaning of the slope of a graph involving position, velocity, or acceleration with respect to time.
recognize the appropriate units of each concept.