1. Distance,_Displacement,_Speed,_and_Velocity.ppt

Let’s Have Fun
“FIND A THING!”
Part I
3
minutes
Timer

Let’s Have Fun
“FIND A THING!”
Part I.
Q1. Was your classmate able to find the object
easily?
Q2. Was the instruction given clear and easy to
follow? What made it easy of difficult to follow?

Let’s Have Fun
“FIND A THING!”
Part II
3
minutes
Timer

Let’s Have Fun
“FIND A THING!”
Part II.
Q3. Was your classmate successful in finding the
object? Was it easy for her or difficult?
Q4. What other details or information included in
the instruction that made it clearer and easier to
follow?

Let’s Have Fun
“FIND A THING!”
Part II.
Q5. In your own words, what is point of reference
and how important it is?

Remember this!
 To describe the motion of an object, you must
first be able to tell exactly where it is
positioned.
 a) describing how far the object is from
the point of reference
 b) describing its direction relative to
that point of reference.

Remember this!
 The distance travelled by an object, how fast
the object is travelling, and the direction in
which the object travels to, are measured
with respect to a POINT OF REFERENCE.

Q1: How far originally is the car
from the tree?
Q2: Before they started moving,
what is the original distance
between the car and the ball?

Q3: If the car moves a distance
of 2 meters in one second, how
far will it be from the tree after 5
seconds?

Q4: Suppose the ball covers a
distance of 1 meter in one
second, how much distance can
it cover in 5 seconds?

 An object is moving if it changes position
relative to a reference point after a passage of
time.
 Objects that are fixed relative to Earth such as a
tree, building, or post make good points of
reference.

Distance
Is the total length of path travelled from
its initial position to its final position. It refers
to how much ground the object has covered
during its motion.
Has magnitude only.

Distance
 Distance (d) – how far an object travels.
 Does not depend on direction.
 Imagine an ant crawling along a ruler.
 What distance did the ant travel?
 d = 3 cm
cm
0 1 2 3 4 5 6 7 8 9 10

Distance
 Distance does not depend on direction.
 Here’s our intrepid ant explorer again.
 Now what distance did the ant travel?
 d = 3 cm
 Does his direction change the answer?
cm
0 1 2 3 4 5 6 7 8 9 10

Distance
 Distance does not depend on direction.
 Let’s follow the ant again.
 What distance did the ant walk this time?
 d = 7 cm
cm
0 1 2 3 4 5 6 7 8 9 10

Displacement
Measures the length of the straight line
that connects the object’s point of origin and
its point of destination.
It has both magnitude and direction.

Displacement
 Displacement (d) – difference between an object’s
final position and its starting position.
 Does depend on direction.
 Displacement = final position – initial position
 d = dfinal – dinitial
 In order to define displacement, we need directions.
 Examples of directions:
 + and –
 N, S, E, W
 Angles

Displacement vs. Distance
 Example of distance:
 The ant walked 3 cm.
 Example of displacement:
 The ant walked 3 cm EAST.
 An object’s distance traveled and its
displacement aren’t always the same!

1. Distance,_Displacement,_Speed,_and_Velocity.ppt

cm
0 1 2 3 4 5 6 7 8 9 10
+
-
Displacement
 Let’s revisit our ant, and this time we’ll find
his displacement.
 Distance: 3 cm
 Displacement: +3 cm
 The positive gives the ant a direction!

Displacement
 Find the ant’s displacement again.
 Remember, displacement has direction!
 Distance: 3 cm
 Displacement: -3 cm
cm
0 1 2 3 4 5 6 7 8 9 10
+
-

Displacement
 Find the distance and displacement of the
ant.
 Distance: 7 cm
cm
0 1 2 3 4 5 6 7 8 9 10
+
-

Displacement vs. Distance
 An athlete runs around a track that is 100 meters
long three times, then stops.
 What is the athlete’s distance and displacement?
 Distance = 300 m
 Displacement = 0 m
 Why?

Speed
 Speed (s) – Rate at which an object is
moving.
 speed = distance / time
 s = d/t
 Like distance, speed does not depend on
direction.

Speed
1. A car drives 100 meters in 5 seconds.
 What is the car’s average speed?
 s = d/t
 s = (100 m) / (5 s) = 20 m/s
100 m
1 s
2 s
3 s
4 s
5 s

Speed
2. A rocket is traveling at 10 m/s. How long does it
take the rocket to travel 30 m?

Speed
3. A racecar is traveling at 85.0 m/s. How
far does the car travel in 30.0 s?

Velocity
 Velocity (v) – speed with direction.
 velocity = displacement / time
 v = d / t
 Has magnitude and direction!
 Magnitude – a measure that has a value

Pulling It All Together
 Back to our ant explorer!
 Distance traveled: 7 cm
 Average speed: (7 cm) / (5 s) = 1.4 cm/s
 Average velocity: (+3 cm) / (5 s) = +0.6 cm/s
cm
0 1 2 3 4 5 6 7 8 9 10
+
-
1 s
2 s
3 s
4 s
5 s

Distance Vs. Displacement
5 m 5 m, North
2 km 2 km, South
7 cm, East
7 cm
10 ft. 10 ft., West

Distance Vs. Displacement
3 m
9 km
10 cm
45 ft.

Speed Vs. Velocity
5 m/s 5 m/s, North
2 km/hr 2 km/hr, South
7 cm/s, East
7 cm/s
10 ft./hr 10 ft./hr, West

Speed Vs. Velocity
15 m/s
25 km/hr
10 m/s
20 km/hr

Distance 5 m
Displacement 5 m, North
Speed 5 m/s
Velocity 5 m/s, North
1.
10 km

Distance 5 m
Speed 5 m/s
2.
20 km/hr

Distance 5 m
Speed 5 m/s
3.
9 km, South

Distance 5 m
Speed 5 m/s
4.
15 m/s, South

Distance 5 m
Speed 5 m/s
5.
14 miles

Distance 5 m
Speed 5 m/s
6.
30km/hr, West

Distance 5 m
Speed 5 m/s
7.
75 km

Distance 5 m
Speed 5 m/s
8.
45 km/hr

Distance 5 m
Speed 5 m/s
9.
7m, East

Distance 5 m
Speed 5 m/s
10.
15 m/s, North

1. Distance,_Displacement,_Speed,_and_Velocity.ppt

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1. Distance,_Displacement,_Speed,_and_Velocity.ppt