Motion
Speed, Velocity,
and Acceleration
Question
 When
can you
determine how fast you
are going in a jet
plane?
Frames of Reference



The object or point from which
movement is determined
Movement is relative to an
object that appears stationary
Earth is the most common
frame of reference
Questions
 What
is the frame of
reference for the sunset?
 What is a frame of
reference?
 What is the most common
frame of reference?
Motion
IN: What is motion?
 Motion is a change in
position relative to a frame
of reference
 Speed is the distance
traveled in a given amount
of time
 Speed=distance

time

Speed
 The
units for speed:
 meters/second (m/sec)
 kilometers/hour (km/hr)
 Speed that does not
change is constant speed
Average speed
Total distance divided by
the total time
 Formula:
 Total distance
total time

Velocity
Speed in a given direction
 Velocities in the same
direction combine by adding
 Velocities in different
directions combine by
subtracting

Interesting fact
 Why
is direction
important? Rockets
are launched in the
same direction of the
earth’s rotation to get
an extra boost of 1800
km/hr to its speed
Questions
 What is motion?
 What is speed? How is
it calculated?
 What is average
speed?
Questions
 How
is velocity different
from speed?
 Which two factors
determine an object’s
velocity?
The Speed Triangle
Distance
Time
Speed
Triangle Explained
 Distance
= Time X Speed
 Time = Distance/Speed
 Speed = Distance/Time
Problems to Solve
1.
2.
If Steve throws the football 50 kilometers
(km) in 3 hours, what is the average speed
of the football?
If it takes Ashley 3 seconds to run from the
batters box to first base at an average speed
of 6.5 meters per second, what is the
distance she covers in that time?
Answers for Questions 1-2
Distance = 50km Time = 3 hr
Speed = distance/time or 50km/3hr
Answer is 16.7km/hr
2. Time = 3 sec Avg Speed = 6.5m/s
Distance = time X speed or 3s X 6.5m/s
Answer is 19.5m
1.
More Problems
3.
4.
Lauren’s SUV was detected exceeding the
posted speed limit of 60 kilometers per
hour, how many kilometers per hour would
she have been traveling over the limit if
she had covered a distance of 10
kilometers in 5 minutes?
Tina’s calculations of the tarantula found
that the spider was able to cover 20
centimeters in 5 seconds, what was the
average speed of the spider?
Even More Problems
5.
6.
Mike rides his motorcycle at an average
speed (velocity) of 20 meters/second for
500 seconds, how far did he ride?
Sarah backstrokes at an average speed of 8
meters per second, how long will it take
her to complete the race of 200 meters
length?
Some real life speed problems
7.
8.
9.
How much time would it take for the
sound of thunder to travel 2000 meters if
sound travels at the speed of 330 meters
per second?
How much time would it take for an
airplane to reach its destination if it
traveled at an average speed of 790 km/hr
for a distance of 5000 kilometers?
An ant can travel approximately 30 meters
per minute. How many meters could an
ant move in 1 hour (60 minutes)?
Resultant Velocity


Velocities in the same direction
combine by adding
Velocities in different directions
combine by subtracting
Acceleration
 The
change in velocity
 Acceleration is measured
in m/sec/sec or m/sec2
 Formula is:
 (final velocity - original
velocity)/time
Deceleration vs. Acceleration
A
decrease in velocity is
deceleration or negative
acceleration
 A distance-time graph for
acceleration is always a
curve
Questions
 What
is acceleration?
 What is the shape of a
distance-time graph for
acceleration?
 What is centripetal
acceleration?
Graphing
Bell Work

Person A and B are running
a race.
 Which line has a greater
slope, A or B?
 Who won the race and ran
faster than the other person?
 How do you know this line
has a greater slope
 What evidence shows this
person ran faster than the
other person?
Practice
Graph
Can you figure out the speed
for Point:
A
B
C
D
E
What is happening to the
motion between point C and
D?
What is happening to the
motion between point D and
E?
Graph for running “The Mile” in
P.E.

Why is the blue line
curved?
 If something is getting
faster or slower what
vocabulary word do
we use?
 The green line
represents what type
of speed?
“The Mile” continued


Can you figure out what
might have happened to the
student represented by the
red line?
Include what is happening
to the time and distance as
the red line is changing.
Newton’s Laws
The Three Laws of
Motion
Momentum
 Momentum is equal to
the mass of an object
times its velocity
 momentum= mass x
velocity
Conserving Momentum
 The
law of
conservation of
momentum states that
the total momentum is
NOT lost, only
transferred
Questions
What is momentum?
 What happens to momentum
as the mass of a moving
object increases?
 What is the formula for
momentum?
 What is the law of
conservation of momentum?
