This presentation can be used in introducing kinematics in 1 dimension. It includes distance, displacement, speed, velocity, acceleration and graphs of motion.
10. What (information? equipment?) do we need in order to
describe the motion of the car?
Clock Reading:
Is time enough to describe “how fast” the car moves?
17. Position + Clock Reading = Event
• I’ll stop the movie and just show you 1
frame - there is a position and clock
reading associated with it.
18. Position + Clock Reading = Event
• I’ll stop the movie and just show you 1
frame - there is a position and clock
reading associated with it.
19. Position + Clock Reading = Event
• I’ll stop the movie and just show you 1
frame - there is a position and clock
reading associated with it.
Instantaneous Position
20. Position + Clock Reading = Event
• I’ll stop the movie and just show you 1
frame - there is a position and clock
reading associated with it.
Instantaneous Position How long is an “instant”?
28. Average Velocity
position “s” (m)
clock reading (or instant) “t” (s)
29. Average Velocity
position “s” (m)
clock reading (or instant) “t” (s)
!!
! ! ! !! !
30. Average Velocity
position “s” (m)
clock reading (or instant) “t” (s)
!!
! ! ! !! !
What if I invert the values? What does it mean?
31. Average Velocity
position “s” (m)
clock reading (or instant) “t” (s)
!!
! ! ! !! !
What if I invert the values? What does it mean?
Create a name for this new defined quantity.
38. Graphs
• What is the big deal? Everyone can learn
how to interpret and construct one.
39. Graphs
• What is the big deal? Everyone can learn
how to interpret and construct one.
• It will help you visualize and solve problems
40. Graphs
• What is the big deal? Everyone can learn
how to interpret and construct one.
• It will help you visualize and solve problems
• You must be very careful on your
interpretation of graphs
41. s vs. t graphs
10
9
position vs. time
8
7
6
position / m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
clock reading / s
42. s vs. t graphs
10
9
position vs. time
8
7
6
position / m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
clock reading / s
43. s vs. t graphs
10
9
position vs. time
8
y = 0.5x + 1.5 R² = 1
7
6
position / m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
clock reading / s
44. s vs. t graphs
10
9
position vs. time
8
7
6
position / m
5
(7,5)
4
3
2
(1,2)
1
0
0 1 2 3 4 5 6 7 8 9 10
clock reading / s
45. 10
9
position vs. time
8
7
6
position / m
5
(7,5)
4
3
2
(1,2)
1
0
0 1 2 3 4 5 6 7 8 9 10
clock reading / s
46. 10
9
position vs. time
8
7
6
position / m 5
(7,5)
4
3
2
(1,2)
1
0
0 1 2 3 4 5 6 7 8 9 10
clock reading / s
47. 10
9
position vs. time
8
7
6
position / m 5
(7,5)
4
3
2
(1,2)
1
0
0 1 2 3 4 5 6 7 8 9 10
clock reading / s
!! !! ! !!
!! ! ! !!!!!" !! !
!! !! ! !!
50. !! !! ! !!
!! ! ! !!!!!" !! !
!! !! ! !!
10
9
position vs. time
8
y = 0.5x + 1.5 R² = 1
7
6
position / m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
clock reading / s
51. !! !! ! !!
!! ! ! !!!!!" !! !
!! !! ! !!
10
9
position vs. time
8
y = 0.5x + 1.5 R² = 1
7
6
position / m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
clock reading / s
52. !! !! ! !!
!! ! ! !!!!!" !! !
!! !! ! !!
10
9
position vs. time
8
y = 0.5x + 1.5 R² = 1
7
6
position / m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
clock reading / s
slope (gradient) = average velocity
53. Take a look at this position vs. time graph!
10
9
8
7
6
position /m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time/s
54. Take a look at this position vs. time graph!
10
9
8
7
6
position /m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time/s
55. Take a look at this position vs. time graph!
10
9
8
7
6
position /m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time/s
56. Take a look at this position vs. time graph!
10
9
8
7
6
position /m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time/s
57. Take a look at this position vs. time graph!
10
9
8
7
6
position /m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time/s
58. Take a look at this position vs. time graph!
10
9
8
7
6
position /m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time/s
when the time interval decreases to zero
we get instantaneous velocity
59. Take a look at this position vs. time graph!
10
9
8
7
6
position /m
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time/s
when the time interval decreases to zero
we get instantaneous velocity
62. 10
9
8
7
position /m 6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time/s
the gradient (slope) of the tangential line at an instant in
time gives you the instantaneous velocity
64. To conclude:
• The slope of the line connecting 2 events in
a positions vs. time graph gives you the
average velocity
65. To conclude:
• The slope of the line connecting 2 events in
a positions vs. time graph gives you the
average velocity
• If the time interval of these events go to
zero, we get a tangential line, at a instant in
time, whose slope is what we call
instantaneous velocity (e.g. speedometer)
69. Uniform Velocity
• same change in position for each (one)
second of the motion.
• a.k.a constant velocity
70. Uniform Velocity
• same change in position for each (one)
second of the motion.
• a.k.a constant velocity
• average velocity is essentially the same as
uniform velocity
71. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time / s
72. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time / s
73. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time / s
74. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time / s
75. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time / s
76. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time / s
Uniform velocity: no change in speed!
77. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time / s
Uniform velocity: no change in speed!
Question: If particle moves at constant 3ms-1 for a time of
9s how much distance has it moved?
78. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time / s
79. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time / s
80. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
time / s
81. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
!"#! ! !!!!! ! !"!
0
0 1 2 3 4 5 6 7 8 9 10
time / s
82. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
!"#! ! !!!!! ! !"!
0
0 1 2 3 4 5 6 7 8 9 10
time / s
Units?
83. Velocity Graphs
10
Velocity vs. Time
9
8
7
velocity / ms-1
6
5
4
3
2
1
!"#! ! !!!!! ! !"!
0
0 1 2 3 4 5 6 7 8 9 10
time / s
Units? ms-1 x s = m
86. Uniform Velocity Graph
• its v vs. t is a horizontal line
• the area below the line represents the
change in position
87. Uniform Velocity Graph
• its v vs. t is a horizontal line
• the area below the line represents the
change in position
• + and - signs may be used to represent
direction of motion
93. Let’s do some physics
analysis
• What is his average velocity? Calculate
94. Let’s do some physics
analysis
• What is his average velocity? Calculate
• What is his top instantaneous velocity?
95. Let’s do some physics
analysis
• What is his average velocity? Calculate
• What is his top instantaneous velocity?
• When in the race does he reach his top
velocity?
96. Let’s do some physics
analysis
• What is his average velocity? Calculate
• What is his top instantaneous velocity?
• When in the race does he reach his top
velocity?
• Any ideas to find his top velocity? and
when?
97. Let’s do some physics
analysis
• What is his average velocity? Calculate
• What is his top instantaneous velocity?
• When in the race does he reach his top
velocity?
• Any ideas to find his top velocity? and
when?
In groups, try to use this chart to extract as much
information as possible and be ready to present your
findings to the rest of the class.
101. Quick remarks about the fastest man alive:
• His top velocity was around 12.3 ms-1( 45 km/h,
28 mi/h)
102. Quick remarks about the fastest man alive:
• His top velocity was around 12.3 ms-1( 45 km/h,
28 mi/h)
• He reached his top speed at around 65 m
103. Quick remarks about the fastest man alive:
• His top velocity was around 12.3 ms-1( 45 km/h,
28 mi/h)
• He reached his top speed at around 65 m
• He took 41 steps in the race (about 4.3 steps
per second at an average step length of 2.5 m,
2.8 at peak velocity)
104. Quick remarks about the fastest man alive:
• His top velocity was around 12.3 ms-1( 45 km/h,
28 mi/h)
• He reached his top speed at around 65 m
• He took 41 steps in the race (about 4.3 steps
per second at an average step length of 2.5 m,
2.8 at peak velocity)
• his record is 0.13s faster than the second fastest
time. Insane!
108. Bugatti Veyron 16.4
Fastest road-legal car in the world
• 0-100 km/h in 2.46s
109. Bugatti Veyron 16.4
Fastest road-legal car in the world
• 0-100 km/h in 2.46s
• Top speed of 431 km/h
110. Bugatti Veyron 16.4
Fastest road-legal car in the world
• 0-100 km/h in 2.46s
• Top speed of 431 km/h
• Cost: U$2,700,000
111. Bugatti Veyron 16.4
Fastest road-legal car in the world
• 0-100 km/h in 2.46s
• Top speed of 431 km/h
• Cost: U$2,700,000
• Number of unit sales in 2010: 40
112. Bugatti Veyron 16.4
Fastest road-legal car in the world
• 0-100 km/h in 2.46s
• Top speed of 431 km/h
• Cost: U$2,700,000
• Number of unit sales in 2010: 40
113. Bugatti Veyron 16.4
Fastest road-legal car in the world
• 0-100 km/h in 2.46s
• Top speed of 431 km/h
• Cost: U$2,700,000
• Number of unit sales in 2010: 40
What can we find out with this information?
115. Free Fall
• Have you heard of the number 10 m/s-2 in
association with free fall?
116. Free Fall
• Have you heard of the number 10 m/s-2 in
association with free fall?
• What does this number mean? What does
it describe?
117. Free Fall
• Have you heard of the number 10 m/s-2 in
association with free fall?
• What does this number mean? What does
it describe?
• Does it have any relation to kinematic
concepts we have defined?
118. Free Fall
• Have you heard of the number 10 m/s-2 in
association with free fall?
• What does this number mean? What does
it describe?
• Does it have any relation to kinematic
concepts we have defined?
• If I drop a ball from rest (zero velocity),
what is the velocity at the end of 1
second? ....
120. Acceleration: the change of velocity per (one) unit of
time
acceleration is a vector unit is ms-2
121. Acceleration: the change of velocity per (one) unit of
time
acceleration is a vector unit is ms-2
!!
!! !
!!
122. Acceleration: the change of velocity per (one) unit of
time
acceleration is a vector unit is ms-2
!!
!! !
!!
123. Acceleration: the change of velocity per (one) unit of
time
acceleration is a vector unit is ms-2
!!
!! !
!!
Note that the velocity on the definition of
acceleration is an instantaneous value (at an instant
in time)
124. Acceleration: the change of velocity per (one) unit of
time
acceleration is a vector unit is ms-2
!!
!! !
!!
Note that the velocity on the definition of
acceleration is an instantaneous value (at an instant
in time)
The acceleration found that way is an average value
127. Acceleration and sign
(+ or -) Direction
• An object moving in the (+) direction
has an acceleration
128. Acceleration and sign
(+ or -) Direction
• An object moving in the (+) direction
has an acceleration
• Same object moving in the (+) direction,
decelerates (slow down)
129. Acceleration and sign
(+ or -) Direction
• An object moving in the (+) direction
has an acceleration
• Same object moving in the (+) direction,
decelerates (slow down)
• An object moving in the (-) direction
accelerates
130. Acceleration and sign
(+ or -) Direction
• An object moving in the (+) direction
has an acceleration
• Same object moving in the (+) direction,
decelerates (slow down)
• An object moving in the (-) direction
accelerates
• Same object moving in the (-) direction
decelerates.
132. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
133. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u
134. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u
+
135. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u a
+
136. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u a
+ =
137. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u a v
+ =
138. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u a v
+ =
If the initial velocity has the opposite sign (direction) as the
acceleration, the object slows down.
139. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u a v
+ =
If the initial velocity has the opposite sign (direction) as the
acceleration, the object slows down.
u
140. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u a v
+ =
If the initial velocity has the opposite sign (direction) as the
acceleration, the object slows down.
u
+
141. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u a v
+ =
If the initial velocity has the opposite sign (direction) as the
acceleration, the object slows down.
u a
+
142. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u a v
+ =
If the initial velocity has the opposite sign (direction) as the
acceleration, the object slows down.
u a
+ =
143. Summary
If the initial velocity has the same sign (direction) as the
acceleration, the object gets faster.
u a v
+ =
If the initial velocity has the opposite sign (direction) as the
acceleration, the object slows down.
u a v
+ =
144. Non-uniform Velocity
Graphs
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
2
1
0
0 1 2 3 4 5 6
time / s
145. Non-uniform Velocity
Graphs
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
2
1
0
0 1 2 3 4 5 6
time / s
146. Non-uniform Velocity
Graphs
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
2
1
0
0 1 2 3 4 5 6
time / s
147. Non-uniform Velocity
Graphs
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
2
1
0
0 1 2 3 4 5 6
time / s
148. Non-uniform Velocity
Graphs
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
2
1
0
0 1 2 3 4 5 6
time / s
149. Non-uniform Velocity
Graphs
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
2
1
0
0 1 2 3 4 5 6
time / s
150. Non-uniform Velocity
Graphs
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
2
1
0
0 1 2 3 4 5 6
time / s
How much is the speed changing each second?
151. Non-uniform Velocity
Graphs
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
∆v = 8 - 5 = 1.5
2
∆t 4-2
1
0
0 1 2 3 4 5 6
time / s
152. Non-uniform Velocity
Graphs
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
∆v = 8 - 5 = 1.5
2
∆t 4-2
1
0
0 1 2 3 4 5 6
time / s
The slope (gradient) is the acceleration
153. What was the change in position in these
5 seconds?
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
2
1
0
0 1 2 3 4 5 6
time / s
154. What was the change in position in these
5 seconds?
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
2
1
0
0 1 2 3 4 5 6
time / s
The area under the line is the change in position
155. What was the change in position in these
5 seconds?
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
4
3
2
1
0
0 1 2 3 4 5 6
time / s
The area under the line is the change in position
156. What was the change in position in these
5 seconds?
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
!
4 !! ! ! !!! ! !"!!!!
!
3
2
1 !! ! !!! ! !"!!
0
0 1 2 3 4 5 6
time / s
157. What was the change in position in these
5 seconds?
10
Velocity vs. Time
9
8
7
6
velocity / ms-1
5
!
4 !! ! ! !!! ! !"!!!!
!
3
2
1 !! ! !!! ! !"!!
0
0 1 2 3 4 5 6
time / s
There was a total displacement of 28.8m in 5 seconds
158. Motion Graphs
30 10
25 8
acceleration / ms-2
velocity / ms-1
20
6
15
4
10
2
5
0 0
0 1 2 3 4 5 6 0 1 2 3 4 5 6
time / s time / s
70
60
50
position / m
40
30
20
10
0
0 1 2 3 4 5 6
time / s