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Look around you- you are likely to see
something in motion.
Even if you don’t see anything moving, motion
is still occurring all around you.
Air particles are moving, the Earth is circling
the sun, and blood is traveling through your
blood vessels.
Reference
Points
A reference point is used to determine the
direction of the moving object.
The earth’s surface is a common reference
point for determining motion.
Reference points can be moving or nonmoving.
Nonmoving objects: mountains
Moving objects: hot air balloon and the zebra.
Motion
Motion is an object’s change in
position relative to a reference
point.
You can describe this motion in
terms of direction: N, E, S, W,
up, down, to the left of , just
beyond, in front of, etc.
Speed
Speed is the
distance
traveled by
an object
divided by
the time
taken to
travel the
distance.
Formula
Measuring
speed
Units used for
measuring
speed can
differ, but will
always be a
distance unit
divided by a
time unit.
Jets: km/h
Cars: mi./h
Snails: cm/s
Falling objects: m/s
 An athlete swims a distance from one end of a
50 m pool to the other end in a time of 25 s.
What is the athlete’s average speed?
1. Write the equation for average speed.
2. Replace the total distance and time with the
values given and solve
S=50m÷25s
S=2m/s
Average
speed
Speed is usually
NOT CONSTANT
Examples:
Cars stop and
go regularly.
Runners go
slower uphill
than downhill.
.
Average speed = total distance
traveled/total time it took.

It took me 1 hour to go 40 km on the
highway. Then it took me 2 more hours to go
20 km using the side streets.
Total Distance: 40 km + 20 km = 60 km
Total Time: 1 h + 2 h = 3 hr
Ave. Speed: total d/total t = 60 km/3 h = 20 km/h
Total _ Dist.
Ave. _ Speed 
Total _ tim e

I ran 1000 m in 3 minutes. Then ran another 1000 m
uphill in 7 minutes. What is my average speed?

Total Dist. =
1000 m + 1000 m = 2000 m

Total Time =
3 min + 7 min = 10 min

Ave speed = total dist/total time =
2000m/10 min = 200 m/min = D
Velocity
Imagine that two
birds leave the
same tree at the
same time. They
both fly at
10
km/h for 5 min, 12
km/h for 8 min,
and 5 km/h for 10
min. Why don’t
they end up at the
same place?
The birds went in different
directions!
Velocity
Definition:
the SPEED of an
object in a
particular direction.
Examples:
An airplane moving
North at 500 mph
A missile moving
towards you at
200 m/s
 What is the difference between
speed and velocity?
Speed is just distance/time.
Velocity includes direction as well.
If you say that an airplane’s velocity is 600
km/h, you would be incorrect. But you could
say the plane’s velocity is 600 km/h south.
 Although the word accelerate is commonly
used to mean “speed up,” the word means
something else in science.
 Acceleration is the rate at which velocity
changes over time.
 An object accelerates if its speed, direction, or
both change.
Acceleration
Acceleration
Acceleration = Final velocity – Original Velocity
Time
Acceleration = Final velocity – Original Velocity
Time
Deceleration = 10 m/ sec – 25 m/sec = -15 m/sec = -5 m/sec/sec
3 sec
3 sec
Deceleration= Final velocity – Original Velocity
Time

In this activity, you will observe one factor that affects the speed
of falling dominoes.
1.
2.
3.
4.
5.
6.
7.
Set up 15 dominoes in a straight line (use the meter stick as a guide). Try
to keep equal spacing between the dominoes.
Use the meter stick to measure the total length of your row of dominoes,
and record the length.
Use a stopwatch to time how long it takes for the dominoes to fall.
Record this measurement.
Predict what would happen to that amount of time if you changed the
distance between the dominoes. Write your predictions.
Repeat steps 2 & 3 several times using distances between the dominoes
that are smaller and larger than the distance used in your first setup. Use
the same number of dominoes in each trial.
Calculate the average speed for each trial by dividing the total distance
(domino row) by the time the dominoes take to fall. S=d ÷ t (round to the
nearest tenth)
How did the spacing between dominoes affect the average speed?
Force
Definition; a push or a
pull
All forces have size
and direction.
A force can change the
acceleration on an
object. It can be a
change in speed or a
change in motion.
Anytime you see a
change in an object’s
motion, you can be
sure it was caused by
a force.
Scientists express force using a unit
called the Newton (N)





Examples of everyday forces used:
Typing on the computer
Walking
Sitting in a chair
These forces don’t necessarily mean that a
motion will occur. For example:
Although we can’t always see
the forces that are there, they
are there!
Can you see the force that
pulls a magnet to a
refrigerator?
Can you see that air around
you that is held near Earth’s
surface by a force called
gravity?
You probably hear the word force used often. People say things such as “That storm had a
lot of force” or “Our football team is a force to be reckoned with.” But what exactly is a force?
In science, a force is a push or a pull. All forces have two properties: direction and
magnitude. A newton (N) is the unit used to describe the magnitude, or size, of a force.
What two properties do all forces have?
Balanced condition, in a tug of war,
when the rope is still is also an
example of balanced force. Let’s
assume you are playing tug of war
with a team. Your team starts with
all its strength and the team on the
other side is also pulling with the
same force but in an opposite
direction. Due to this the flag in the
middle of the rope does not move.
This is because force from both the
sides cancels out each other, the net
force is zero and we get a condition
of balanced force.
Net Force
= 0 Newtons (N)
=5N
Usually more than one force is acting on
an object. Net force is the combination of
all of the forces acting on an object.
Usually more than one
force is acting on an object.
The net force is the
combination of all of the
forces acting on an object.
If you pull a desk towards
you as your friend pushes it
towards you, the forces act
in the same direction. You
would ADD these forces to
determine the net force
since they are acting in the
same direction!
Friction
Work
Work- a force acting
through a distance
In order for work to be
done on an object, a force
must move it
Work is the amount of
force applied to an object
times the distance the
object moves in the
direction of the force
If an object doesn’t
move, no work is
done
If an object doesn’t
move in the direction
of the force, no work
is done
Work = force x distance (w = f x d )