Speed and Velocity
What is motion?
• Answer  Motion occurs
when an object changes its
location in space over a
period of time.
• Did you know that you are
spinning 1600 km/hr (1000
miles/hour) while you are sitting
in this classroom? Do you feel
dizzy? Probably not.
• The reason you are not dizzy is
that motion can only be
detected relative to a FRAME
OF REFERENCE such as
some other object or point in
space. The most common
frame of reference is the
EARTH.
Speed Definition and Formula
Definition:
 Distance traveled
over a period of time.
Formula:
Speed = Distance
Time
Units: m/s or
km/hr or
miles/hr
Round to the
nearest tenth!
Example #1
Mr. Lamberton on a bad day, can pitch a
baseball from the mound to home plate, a
distance of about 20 meters in 0.624 seconds.
How fast is his pitch?
Speed = distance
time
Speed = 20 meters
0.624 sec
Speed = 32.1 m
s
Example #2
Mrs. Kerr walks home from school at a
speed of 1.25 m/s. If it takes her 6
minutes (360 seconds) to walk home,
how far away is her house?
Speed = distance
time
Speed x time = distance
1.25 m x 360 seconds = 450.0 meters
s
Example 3
An attacking hawk has
a speed of 100 m/s.
How much time did
it take the hawk to
get dinner if he was
flying at an altitude
of 50 meters when
he spotted a mouse
scampering on the
ground?
Speed = distance
time
Time = distance
speed
Time = 50 meters
100 m
s
Time = 0.5 seconds
Graphing Speed
Constant
Speed
(distance and time
increase as an
even proportion)
Graphing Speed
Stopped
(distance stays the
same while time
continues)
Graphing Speed
Acceleration
(as time continues,
distance
INCREASES
rapidly)
Graphing Speed
Deceleration
(as time continues,
distance
DECREASES
rapidly)
Velocity Definition and Formula
Definition:
 Distance traveled over a
period of time.
 What makes velocity
different from speed is
that you must have a
DIRECTION.
Formula:
Round to the
nearest tenth!
Speed = Distance
Time
Units: m/s or km/hr or
miles/hr
Example:
If you walk 4 km/hr in an
easterly direction your
velocity would be 4 km/hr
EAST!
Example 1
Bob ran a marathon
(26 miles) in 4 hours,
what was his
average speed?
(Use speed formula)
Speed = distance
time
Speed = 26 miles
4 hours
Speed = 6.5 miles
hr
Example 2
Jill drove her car 10
hours due South and
traveled 800 miles,
what was her
average velocity?
(Use speed formula)
Velocity = distance
time
Velocity = 800 miles
10 hours
Velocity = 80.0 miles
hr
SOUTH
Example 3
A racecar
completed a 500mile race in 4 hours,
what was the
average speed of the
car? (Use speed
formula)
Speed
= distance
time
Speed
= 500 miles
4 hours
Speed
= 125.0 miles
hr