Describing Motion
Picturing Motion
Motion Diagrams
– A series of images
of a moving object
Particle Model
Particle Model
– Replacing an object by a single point.
– Example  Ticker Timer Lab
Vectors and Scalars
A quantity that has only magnitude
is referred to as a scalar quantity
A quantity that has magnitude and
direction is referred to as a vector
quantity
– The arrow head indicates direction,
while the length of the arrow indicates
magnitude
Vector Diagrams
Interpret the motion of the following
diagram.
What would a gradually increasing
velocity vector look like? Draw it.
Time Intervals and Displacement
Displacement is the change in
position of an object (defines the
distance and direction between two
positions)
– Therefore d =df - di
Time interval is the difference
between ti and tf
– Therefore t =tf – ti
Velocity and Acceleration
Average Velocity
– Simply the slope of a Position vs. Time
Graph
V = d / t = (df – di) / (tf – ti)
Average Acceleration
– Simply the slope of a Velocity vs. Time
Graph
a= v / t = (vf – vi) / (tf – ti)