Relative motion
How motion of an object is described depend on
the reference frame in which it is observed.
A person is walking on a train, from the back of a car
to the front. The velocity of the person with respect to
(wrt) the train is different than

The four equations of kinematics
(Constant acceleration)
Free fall near Earths surface
Gravity: objects fall toward centre of Earth with
acceleration a which is independent of mass.
Neglect air resistance
Near Earths surface, a almost independent of he

The Four Equations of Kinematics
(Constant acceleration)
Homework: Cutnell & Johnson 9th Edition, Problem 2.23
Two motorcycles are traveling due east with different
velocities. However, four seconds later, they have the
same velocity. During this four-sec

Homework: Cutnell & Johnson 9th Edition, Problem 1.37
Homework: Cutnell & Johnson 9th Edition, Problem 1.37
45
35
55
Kinematics in one dimension (motion in a line)
Measure the position of an object at any time t with
respect to an origin. The position

Graphical analysis of v and a
Record position
along x-axis as a
function of time
Time (s)
Position (m)
0
+2
1
0
2
-2
3
-4
Graph position
versus time
Slope of line is
average velocity
x
2 m s
t
Granny was moving at a constant velocity, so the
average vel

Homework: Cutnell & Johnson 9th Edition, Problem 2.68
A bus makes a trip according to the position-time graph
shown in the drawing. What is the average velocity
(magnitude and direction) of the bus during each of the
segments A, B, and C? Express your ans

Cutnell & Johnson 8th Edition, Problem 4.33
Some people are riding in a hot air balloon. The
combined mass of the people + balloon is 310 kg. The
balloon is motionless in the air because the downward
acting weight of the people + balloon is balanced by an

The projectile will follow a parabolic path:
Often, v0y 0. Example: a projectile launched from the
ground at angle .
Range = horizontal distance between launch point and
landing point, when they are at the same height.
Let t = time in air. Then R = v0xt
A

Newtons first Law (N1)
An object continues in a state of rest or in a state of
motion at a constant speed along a straight line,
unless compelled to change that state by a net force.
Net force: vector
sum of all forces
acting on an object.
Individual forc

Homework: Cutnell & Johnson 9th Edition, Problem 1.6
Consider the equation v =(1/3)zxt2. The dimensions of the
variables v, x, and t are [L]/[T], [L], and [T], respectively. The
numerical factor 3 is dimensionless. What must be the
dimensions of the varia