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
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
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