Third Quarter (3rd) Topics in Science 7!

SCIENCE 7
JADY CLAIRE J. LULLEGAO

50%- WRITTEN TEST
50%- PERFORAMNCE OUTPUT
TOTAL: 100 %
How you are being rated or graded?

COMPONENTS:
Quarter I- DIVERSITY OF MATERIALS INTHE
ENVIRONMENT
Quarter II- LIVINGTHINGS ANDTHEIR
ENVIRONMENT
Quarter III- ENERGY IN MOTION
Quarter IV- EARTH AND SPACE

CONTENT STANDARD
The learners demonstrate an
understanding of motion in one
dimension.
PERFORMANCE STANDARD
Conduct a forum on mitigation
and disaster risk reduction.

What is energy?
the capacity
for doing
work.

What is motion?
A continuous
change in position
with respect to a
reference point for a
particular time
interval.

All Motion is relative
•All motion is relative to a
reference.
•This means that we
describe motion of an
object relative to some
other object

A reference point is a
place or object used for
comparison to determine
if something is in motion.

All Motion is relative
• In our environment, the reference for motion
is the earth’s surface, and speeds are
measured relative to the earth
• The earth moves at 107,000 km/h relative to
the sun

Energy at rest
OR
Energy in Motion

Can you consider this car in
motion?

Can you consider these
boys in motion?

Can you consider the bus in
motion?

Can you consider this man
in motion?

Can you
consider this
babies in
motion?

Lance walked 12.3 m to Martin’s
house and 0.25 meters to Rinch
House and ended with 37 meters
to Quint House.What is the total
distance of Lance?

How are we going to describe motion?

Describe the motion of an
object in terms of distance or
displacement, speed or velocity,
and acceleration
S7FE-IIIa-1
OBJECTIVE

DISTANCE
AND
DISPLACEMENT
LESSON 1

Objectives:
1.Differentiate distance from
displacement; and
2.Compute for the distance and
displacement of a given problem.

IS DISTANCE AND
DISPLACEMENT THE
SAME?

Comparison:
distance
• Refers to the length of the
entire path the object
travelled.
displacement
• Refers to the shortest
distance between the object’s
two positions, like the
distance between its point of
origin and its point of
destination, no matter what
path it took to get to that
destination.

Do you have a sense of direction?
Positive
+
Positive +
Negative
-
Negative -

Let’s have an example:
In this
example, the
dog ran 10 m
to the east,
then 5m to the
South and
another 10 m
to the west.

How far did the dog travel ?
Step 1. Find the given
Given: 10 m East
5 m South
10 mWest
Step 2. What is Asked?
Total Distance=?
Displacement=?
Step 3. What is the Formula
Distance = 𝑑1 + 𝑑2 + 𝑑3
Displacement = 𝑑1 + 𝑑2 + 𝑑3
Step 4. Write your Solution
Distance= 10m + 5m + 10m
= 25 meters is the total distance
covered by the dog

What is the dog’s displacement?
Displacement= 5 m – 0 m
= 5 meters
We can also follow this format:
Displacement= 10m + (– 5m )+(– 10 m)
=5 meters +(-10m)
= - 5 meters
= 5 meters to the south is the displacement of the dog.

Broken line- Distance Continuous line- Displacement

Activity 3.1
– MY
HOME TO
SCHOOL
ROADMAP
After performing this
activity, you should be
able to make a
roadmap that shows
how you get to school
from your house.

Procedure:
1. Devise a way to easily measure distance.
2. Gather the data you will need for your roadmap to estimate the
distance to your school from your house. Make sure that you
take down notes of all names of the roads, landmarks, corners,
posts and establishments you pass by. Record your data
properly.
3. Using your gathering data, draw your house-school roadmap
on a one whole sheet of paper. Decide on the most convenient
scale to use when you draw your roadmap. An example is
shown below.
Scale: 1 cm = 1 km

4. Label your roadmap properly, including names of
the roads, establishments, etc. Specify also the
length of the road.
5. Finally, let your teacher check again your work.

Questions:
1.What is the total length of your
travel from your house to your school?
2.What is the total displacement of
your travel?

Quiz!
A. IDENTIFICATION: Identify if the following quantity
below is distance or displacement.
1. 16 m to the west
2. 15 km upward
3. 25 inch
4. 3 ft. right
5. 72 cm

Review •What is motion?
•How do distance
differ from
displacement?

Objectives 1. Differentiate Speed
fromVelocity; and
2.Solve for the speed and
velocity of an object in
motion.

Activity 3.2 FunWalk
Objective:
After performing this
activity, you should be
able to gather data to
determine who walks
fastest.

Activity 3.2 FunWalk
Materials:
• Stopwatch/ cellphone
• Pencil and paper for
recording
• Pentelpen and Manila
Paper for reporting

Procedure 1. Start by choosing a spacious
place to walk straight.
2. Half of the group will walk
while the other half will
observe and record data.
3. Mark on the ground the
starting line. All participants
must start from the starting
line at the same time.

Procedure 4. Upon receiving the go
signal, all participants
must start to walk as fast
as they could.The other
members should observe
closely as the participants
walk and determine who
walks fastest.

Procedure 5. Repeat step 4 but this
time, collect data to
support your
conclusion. Discuss
within the group how
you are going to do this.

Example : Both Mr Rabbit and Mr Tortoise
took the same round trip, but Mr
Rabbit slept & returned later.

Who is right?
Me, as I spent
less time on the
trip.
No, I travelled
more distance every
second I ran.
Who runs faster?

Speed
How can we describe how fast an object
moves?
E.g. A car travels 90 km in 1 hour.
We say that the car travels at a speed
of 90 km/hr.

Speed
Speed is a measure of how fast something
moves.
Speed = distance travelled per unit of time
SI unit: m/s or km/h (for long distances)
How can we describe how fast an object moves?
𝑆𝑝𝑒𝑒𝑑 =
𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒
𝑡𝑖𝑚𝑒

Sample problem 1:
Hannah went running a distance of 120 m in 30 s?
What was Hannah’s speed?

Sample problem 1:
Hannah went running a distance of 120 m in 30 s?
What was Hannah’s speed?
Solution:
v =
𝑑
𝑡
v =
120 𝑚
30 𝑠
v = 4 m/s

and speeds up again to 60 km/.
1.1 Average speed
Its average speed over the whole journey
overall distance travelled
total time of travel
slows down to 0 km/h,
A car travels at 50 km/h,
Average Speed=

Question 1 •A bug crawls 10 m
in 5 sec. What
was the bug’s
approximate
speed in m/sec?
Answer:
2 cm/sec

Average speed does not tell the variations
during the journey.
On most trips, the speed at any instant
is often different from the average
speed.
Average speed

1.2 Instantaneous speed
= speed at any instant
Instantaneous speed
The word ‘speed’ alone  instantaneous
speed
Instantaneous speed
 distance travelled in an extremely short
time interval

Speedometer tells the car’s speed
at any instant!
Instantaneous speed

Question 2
( )
Average speed =
10.49 s
= 9.53 m/s
100 m
The world record for women’s 100-m
race is 10.49 s.
What is the average speed?

ASSIGNMENT:
1. Lawrence runs in SJNHS quadrangle
and covered 115 meters for 45 seconds.
What is the speed of Lawrence?
2. Jared started his run with a speed of 65
meter per second and end with 50 meter
per second.What is the average speed of
Willyboy?

Review!
Sit down if the statement
describes DISTANCE, Stand up if
the statement describes
DISPLACEMENT, Jump if the
statement describes SPEED.

Review!
1. Refers to the length of
the entire path the object
travelled.

Review!
2. Refers to the shortest distance
between the object’s two positions, like
the distance between its point of origin
and its point of destination, no matter
what path it took to get to that
destination.

Review!
3. Describe how fast
an object moves

Velocity
rate of change of displacement.
a speed in a given direction or
velocity a vector
quantity
direction
magnitude
(speed)
Velocity is...

speed = 300 km/h
direction = west
Train engineers use
speed only.
a.Speed with direction
Pilots use velocity
(direction & speed).
speed = 90 km/h

Because velocity depends on direction as well
as speed, the velocity of an object can change
even if the speed of the object remains
constant.
Velocity
2.1
Describing Motion
The speed of this car
might be constant,
but its velocity is not
constant because the
direction of motion
is always changing.

110 km/h to
the West
150 km/h
NE

Speed Velocity
Change in direction

Average velocity
Velocity=
Displacement
elapsed time
direction of velocity = direction of overall displacement
Velocity= Final Position- Initial Position
Final Time- Initial Time

Sample problem:
What is the runner’s average
velocity if his position changes from
15 m east to 40 m east for 5
seconds time interval?

Sample problem:
What is the runner’s average velocity if his position changes
from 15 m east to 40 m east during a three-second time
interval?
Solution:
v =
𝑓𝑖𝑛𝑎𝑙 𝑝𝑜𝑠𝑖𝑡𝑖𝑜𝑛−𝑖𝑛𝑖𝑡𝑖𝑎𝑙 𝑝𝑜𝑠𝑖𝑡𝑖𝑜𝑛
𝑒𝑙𝑎𝑝𝑠𝑒𝑑 𝑡𝑖𝑚𝑒
v =
40 𝑚−15 𝑚
3 𝑠
v =
25 𝑚
3 𝑠
v = 8.3 m/s, East

Sample problem:
What is the runner’s average
velocity if his position changes from
3 m east to 30 m east during 5
seconds time interval?

Question 3 •A student runs around
a circular track that is
1000m in length in a
time of 30 secs. What
is the average velocity
of the student?
0 m/min
If the student runs completely
around the track, they are back
where they began. So their overall
displacement is zero.

Question 3 •A student runs from 4
meters to 53 meters in
length in a time of 7
secs. What is the
average velocity of the
student?
0 m/min

Question 4 Which of these is a correct
velocity?
A. 55 miles per hour, North
B. 15 kilometers per second
C. 30 meters per second east
D. 400,000,000 meters per
hour

Objectives 1. Define Acceleration;
and
2.Solve acceleration of
the given problems.

Acceleration
When an object
moves faster and
faster,
its speed is
increasing (velocity
changed).

Acceleration
When an object
moves slower
and slower,
its speed is
decreasing (velocity
changed).

When an
object changes
direction,
Acceleration
its velocity
changes too.

Acceleration
Acceleration measures the change in velocity
Acceleration = velocity per unit time
direction speed
overall change in velocity
total time taken
= m/s2
Unit: m/s/s
vector quantity
=

If a car accelerates at 2 m s–2, what does that mean?
Acceleration
t = 1 s v = 2 m s–1,
v = 2 m s–1
v = 0
t = 2 s v = 4 m s–1,
v = 2 m s–1
v = 6 m s–1,
v = 2 m s–1
t = 3 s
1 m
t = 0
3 m
5 m

Tommy accelerates from 20
m/s at 15 sec (t1) to 40
m/s at 60 sec (t2).
Question
What is his avg. acceleration between t1
and t2?
Avg. acceleration
=
40 m/s – 20 m/s
60s – 15 s
20 m/s
45 s
=
= .44 m/s2

Differentiate quantities
in terms of magnitude
and direction;
S7FE-IIIa-2
OBJECTIVE

MOTIVATION
Direction:Arrange the jumbled letters to form a word.
O IT O N M
F E R E N E C E R
O PT N I
C S L A A R
RV O ET C

MOTIVATION
ANSWERS
MOTION
REFERENCE
POINT
SCALAR
VECTOR

Sub-objectives
At the end of the lesson, you will be able to:
• Identify if an object is in motion or not; and
• Classify if the given quantity is scalar or vector.

MOTION
• An object is in motion if its distance from another
object is changing.
• Reference Point is a place or object used for
comparison to determine if something is in motion.
• In other words…. An object is in motion when it
changes position relative to a REFERENCE POINT.

Types of quantities
The magnitude of a quantity tells how large the quantity is.
There are two types of quantities:
1. Scalar quantities – have magnitude only.(Distance and
speed)
2. Vector Quantities- have both magnitude and
direction.(Displacement and velocity, acceleration)

DESCRIBING
MOTION
THROUGH
GRAPHS

Create and interpret visual
representation of the motion
of objects such as tape
charts and motion graphs;
S7FE-IIIb-3
OBJECTIVE

Supposed you were having your on-the-job training in a private
investigating company. You were asked to join a team assigned to
investigate a “hit and run” case. The alleged suspect was captured by
the CCTV camera driving down a road leading to the place of incident.
The suspect denied the allegation, saying that he was then driving very
slowly with a constant speed. Because of the short time difference
when he was caught by the camera and when the accident happened,
he insisted that it was impossible that he would already be at the place
when the crime happened. But when you were viewing the scene again
on the camera, you noticed that his car was leaving oil spots on the
road. When you checked these spots on site, you fond out that they are
still evident. So you began to wonder if the spots can be used to
investigate the motion of the car of the suspect and check whether he
was telling the truth or not.
ACTIVITY 3.3
DOING DETECTIVE WORK

Materials Needed:
•Ruler
•Paper strips with dots
•Cutter or pair of
scissors

4. Cut the strips at each drop starting
from the first to the last drop, and
paste them side by side on a graph
paper to form a tape chart as shown
in figure 12.
Q25. How do the lengths of the tapes
compare?
Q26. if each tape represents the
distance travelled by the object for 1
second, then what “quantity” does
each piece of tape provide?
Q27. What does the chart tell you
about the speed of the car?

Q30. How does
your distance-
time graph
look like?

7. Join the mid-point of the tops of the tapes
with a line.You have now converted your
tape chart to a speed-time graph.
Q31. How does your graph look like? How is
this different from your graph in Figure 13?
Q32. How will you interpret this graph in
terms of the speed and acceleration of the
moving car?
Q33. If you found out in your investigation
that the arrangement of oil drops left by the
car is similar to what you used in this activity,
was the suspect telling the truth when he said
that he was driving with constant speed?

Infer that waves
carry energy;
S7LT-IIIc-4
OBJECTIVE

CLASSROOM
RULES
1. Please observe silence during
discussion.
2. Be cooperative and follow instruction.
3. Raise your right hand if you want to
answer.
4. Noisy students will get minus 1 on their
written output or summative.

Activity 1: Charades
1. One word
2. English
3. One Syllable

Learning outcomes:
1. Infer that wave carries energy
2. Demonstrate how wave carries energy
in the different types of waves.
3. Relate the existence of waves in real
life.

• repetitive movement
• material waves travel through
• solid, liquid or gas
• spreading

Activity 2: “Let’s make a wave”
The class will be group into 3 and will make
longitudinal, transverse and surface waves.
The group will be given 15 minutes to finish the
activity
Members who didn’t participate will have a deduction of
points.
The group will have 1 representative to present
their findings and a leader to lead the group
1.
2.
3.
4.

Group 1: “Transverse Waves”
Materials:
• Rope
• Ribbon
• Activity sheet
• Manila Paper
• Marker
Instruction:
1. Follow Procedure
2. Answer the
Questions on the
activity sheets.

Group 2: “Longitudinal Waves”
Materials:
• Slinky
• Ribbon
• Activity sheet
• Manila Paper
• Marker
Instruction:
1. Follow Procedure
2. Answer the
Questions on the
activity sheets.

Group 3: “Surface Waves”
Materials:
• Basin filled with water
• Paper Boat
• Activity Sheet
• Marker
• Pentel Pen
Instruction:
1. Follow Procedure
2. Answer the
Questions on the
activity sheets.

Question?
What is the similarity of the 3
activities?
1.

• it is a means of transferring energy from one place to
another.
• Carrier of energy
• It can be describe as disturbance that travels through a
medium or transport energy from one location to another.
• waves are classified into different types according to their
natures: Mechanical and Electromagnetic
What is a wave?

•Sound
•Light
•Water
•Radio
•Seismic

Question?
What is the source of the wave pulse in
group 1, 2 and 3?
2.

Question?
How do we know that waves carry
energy?
3.

Question?
What happens when wave passes by?
4.

Question?
What are the 3 types of waves?
5.

Waves are classified into different types
according to their natures :
Surface Waves
Needs medium
Do not need a
medium

Waves are classified into different types
according to their natures :
Mechanical Electromagnetic
e.g. Water waves, waves on a rope,
sound
e.g. Radio, X-Rays, Light
Must have a substance to travel
through
Cannot travel in a vacuum
Does not need a substance to travel
through but can travel through
various substances
Can travel in a vacuum
Vibrations passed on from molecule
to molecule
Travel at very fast speed in a
vacuum: 3 × 108 m/s

Mechanical Waves
• Waves that use matter to transfer
energy:
• Travel through air, as well as
solids, liquids and other gases.
• No matter, no wave…..like in
outer space.

Electromagnetic Waves
• Waves that do not need a medium
(matter) to travel in.
–Can travel in a vacuum (like outer
space) as well as air, water and glass,
but can be absorbed by opaque
materials
–Light, X-rays, RadioWaves

Transverse Waves
A wave where the direction of the vibration
is perpendicular to the direction in which
the wave travels.

Transverse Waves
perpendicular
Up
and
down
Energy direction

Longitudinal Waves
A wave where the direction of the vibration
is parallel to the direction in which the
wave travels.

Longitudinal Waves
parallel
Back and forth
Energy direction

Surface Waves
A combination of transverse and
longitudinal wave where the results of the
motion is in circular pattern.

Activity 3: Let’s sum Up!
1.What is a wave?
2.What is the source of the wave?
3.What are the 2 major types of
waves?
4.What are the 3 classification of
mechanical wave?

Activity 4: “Tell me something”
Question:
1.Can you identify the picture?
What does it show?
2. Does earthquake generate waves?
3. Why does Philippines
always experience
earthquake?
4. What are you going to do to
lessen the negative effects this
unfortunate events may
brought?

1.What do you call a disturbance that
moves away from a source and carries
energy with it?
a.Motion
b.Wave
c.Period
d.Vibration

2. Which of the following statements
is correct?
a.Waves are stationary and do not possess any energy.
b.Waves are purely visual phenomena and do not involve
energy transfer.
c.Waves transfer energy from one place to another.
d.Waves only carry energy when they are observed by
humans

3. Which of the following situations shows that
waves carry energy?
a.A lightning can strike anytime of the day.
b.A loud thunder can be heard even from afar.
c.Two waves can combine to form greater
wavelength.
d.A big ship sailing in a stormy night rock violently
in the waters.

4. The following statements demonstrate Mechanical
wave, which of the following is NOT?
a. by generating through vibrations of an
electric field and magnetic field
b. by creating disturbance in a body of water
c. by moving a piece of spring back and forth
d. by setting a rope in motion through up and
down movement

5.Earthquake generates longitudinal,
transverse and surface waves. What are you
going to do to lessen the result of this
unfortunate events?
a.Be prepared always.
b.Have an emergency plan.
c.Follow the drop, cover and hold.
d.All of the above.

6.What is the direction of the wave to the
direction of the energy in the longitudinal
wave?
a. Perpendicular
b. Parallel
c. Circular
d. Both a and b

7. What is the direction of the wave to the
direction of the energy in the transverse
wave?
a. Perpendicular
b. Parallel
c. Circular
d. Both a and b

8. What is the direction of the wave to the
direction of the energy in the surface waves?
a. Perpendicular
b. Parallel
c. Circular
d. Both a and b

Identification
9. It is a classification of wave that
needs medium for wave to travel.
10. It is a classification of wave that
does not need a medium to travel.

Assignment
Direction: Write on a ½ crosswise sheet of paper
your answers on the following questions:
1.What are the parts of the transverse and
longitudinal wave?
2.Enumerate and define the characteristics of the
wave?

Identification:Write the missing word in your paper.
• A 1.wave is a means of transferring energy from one
place to another
• There are two major types of waves:
• 2. Mechanical & 3. Electromagnetic Waves
• There are 3 minor types of waves:
4.Transverse, 5. Longitudinal, & 6. Surface.
• A longitudinal wave is one in which the direction of
vibration is 7. parallel to the direction of propagation.
• A 8.Transverse wave is a one in which the direction of
vibration is perpendicular to the direction of
propagation.

•The position at
which the wave
is at rest.
•Imaginary line
that represents
equilibrium

•Valley between
two waves, is
the lowest
point.

• The horizontal distance,
either between the crests
or troughs of two
consecutive waves.
• Denoted by the symbol
lambda “ λ ” and
measures in meters.

• Measure of energy.
• the distance from the
equilibrium (rest point)
to the trough or crest.

5. Wave Height
•A vertical
distance
between a
wave's crest and
the next trough.

Identify the different parts of a wave.
1._______
2._______
3._____
4.____
5.____

Relate the
characteristics of
waves;
S7LT-IIId-6
OBJECTIVE

1 complete cycle = 1 wavelength
A B C D E
F G

How many complete waves passes
through?
6 complete cycle

How many complete waves passes
through?
5 complete cycle

1. Frequency (f )
• Is the number of
complete waves or
cycles of oscillation
in a given period of
time
• Measured is hertz

2. Period
•It is the time it
takes to complete
one full cycle.
•Measured in
seconds

3. Wave Speed
• A measure of how fast a wave is moving.
• For mechanical waves it depends on the
state of matter.


Symbols and units
Variable Symbol Unit Symbol
for Unit
Frequency f Hertz Hz
Wavelength 
(“lambda”)
metre m
Velocity or
Wave Speed
v
(or c for light)
metre/second m/s
Time T second s

The relationship between
frequency, velocity and wavelength
c = f 
or
v = f 

What happens to frequency if
the wavelength increases?

What happens to frequency if
the wavelength decreases?

What happens to wavelength if
the frequency decreases?

What happens to wavelength if
the frequency increases?

1.Which of the following characteristics of wave
determines the amount of energy it carries?
A.amplitude
B.frequency
C.wavelength
D.wave speed

2. Which of the following shows the effect of
increasing the frequency of the wave?
A.increase in the amplitude
B.increase in the wavelength
C.decrease on the speed
D.decrease in the wavelength

3. Through the same medium, what happens to
the speed of the wave as frequency increases?
A.increases
B.decreases
C.remains the same
D.cannot be determined

4. What characteristic of wave is constant for all
types of electromagnetic wave?
A.amplitude
B. frequency
C. wavelength
D.wave speed

5. How does the wavelength affect the frequency of the
wave?
A.as wavelength increases, frequency rises
B. as wavelength increases, frequency increases
C. as wavelength decreases, frequency increases
D.as wavelength decreases, frequency decreases

1.Wavelength
2. Frequency
3. Amplitude
4. f
5. 
6.T
7. Hertz
8. m/s
9. decreases
10. decreases

206
What is
this?
What sound
it make?

208
What sound
does this
make? • How does it
make the
sound?

209
What sound
does this
make?

Sound
Waves
• Are mechanical waves that need a
medium to be propagated. Vibrations
of the medium create a series of
compression and rarefaction which is
longitudinal waves.

Where we
can’t
produce
sound?

214
Space
Walk
We cannot
produce
sound in
outer
space.
NASA picture

Describe the characteristics
of sound using the concepts
of wavelength, velocity, and
amplitude;
S7LT-IIID-7
OBJECTIVE

What is
wavelength,
velocity and
amplitude?

Activity 1
My Own Sounding
Box

OBJECTIVES:
1.Demonstrate how sound is
produced; and
2.Identify factors that affect
the pitch and loudness of
the sound produced.

QUESTIONS:
Q1. What physical signs did you observe when you
plucked each rubber band? Did you hear any
sound? What produced the sound?
Q2. How different are the sound produced by each
rubber band with different thickness?
Q3. Are there changes in the note when you
plucked the stretched band?
Q4. Arrange the rubber bands in sequence from the
highest note to the lowest note produced.

Where does speed travels faster?
Sound travels faster
in solid
Sound travels better
in liquids.
Sound travels
slowest in gases.

22
2
Whales sing
to each
other.
• Sound
travels
through
water.

How sounds are made…
 Sound is produced when matter vibrates.
 As an object vibrates, it gives energy to the
particles of matter around it.
 Sound is a longitudinal wave.
 It moves with a series of compression and
rarefactions.

Anything that vibrates produces sound.
When you speak, your vocal cords vibrate.
Particles of air simply move back and forth.
A radio would NOT work in outer space because there is
not any medium for sound to travel through.
“If a tree falls in the forest and no one is present to hear
it, is there a sound?”

FACTORS
AFFECTIN
G THE
SPEED OF
SOUND
• 1. Atmospheric pressure
• -There are more molecular
interactions that happen in hot air.
This is because the hot particles of
air gain more kinetic energy and so
there is also an increase in the mean
velocity of the molecules. Since
sound is a consequence of energy
transfer through collisions and faster
collisions mean faster sound.

FACTORS
AFFECTIN
G THE
SPEED OF
SOUND
• 2. RELATIVE HUMIDITY
• -Sound travels faster in a less
dense substance.
• - Humid days, sound travels more
slowly since the air density is high.
• - Dry days, sound travels faster,
particles are more responsive
speedily transferring energy from
one particle onto the next.

FACTORS
AFFECTIN
G THE
SPEED OF
SOUND
• 3. ATMOSPHERICTEMPERATURE
Temperature
a. Sound travels slower in lower
temperature
b. Sound travels faster in higher
temperature
Average speed of sound in
air = 340 m/s

Medium Speed (m/s)
Air 343
Helium 972
Water 1500
Steel 5600

Explain sound production in
the human voice box, and
how pitch, loudness, and
quality of sound vary from
one person to another;
S7LT-IIIe-8
OBJECTIVE

Activity 2
Properties and
Characteristics of
Sound

1. Loudness
• physiological sensation from a sound
that varies from one person to another.
• It depends on a person’s sense of
hearing, his or her distance from the
source and the material through which
the sound travels.

Loudness
Chart
Loudness
is related
to the
amount of
energy
carried by
a wave.

2. Intensity
• depends on the displacement of the sound
waves.
• It is measured in terms of the amount of energy
per second, that is, the power delivered per
unit area of a surface. (W/𝑚2
)

3. Quality/Timbre- the
distinct characteristics of
sound that enables you to
identify the source of the
sound.

4. Pitch- refers to the highness or lowness of
a tone. It is related to frequency. Higher
frequency sounds such as those from violins
and piccolos produce a high pitch, while
lower frequency sounds such as those from
drums or strings bass produce a low pitch.

High Pitch Low Pitch
High Amplitude
High Intensity
Shorter Wavelength
Low Amplitude
Low Intensity
Longer Wavelength

Doppler
Effect
• Police car speeding by:
– Higher pitch as approached, lower
pitch as moving away.
• Change in pitch is referred to as
the Doppler effect.
– Occurs whenever there is motion
between the source of a sound and
its receiver.
– Source or receiver must be in
motion.

Doppler
Effect
• Police car moving towards you, pushing waves
together causing:
– Shorter wavelengths, higher freq., higher pitch.
• Police car moving away from you, spreading waves
out:
– Longer wavelengths, lower freq., lower pitch

Describe how organisms
produce, transmit, and receive
sound of various frequencies
(infrasonic, audible, and
ultrasonic sound);
S7LT-IIIe-9
OBJECTIVE

For Sound
to be
heard…
• You need 3 things:
– 1. a source that produces the sound
– 2. a medium to transmit the sound
– 3. an organ of the body that detects
the sound
• Sound enters the outer ear,
vibrates eardrum, enters middle
ear and vibrates liquid-filled inner
ear.

Outer Ear
• The outer ear acts as funnel for the waves.
• The waves travel through the ear canal and hit
the lightly stretched membrane called the
eardrum causing it to vibrate.
• The vibrations then
enter the middle ear.

Middle Ear • The middle ear contains the 3
smallest bones in the body.
– hammer, anvil, stirrup
• The vibrations travel
through the 3 bones
and are transmitted to
a liquid-filled inner ear.

Inner Ear
• The inner ear contains the
cochlea.
• Cochlea is snail shaped
– Contains liquid and hundreds of
cell attached to nerve fibers
– The nerve fibers form one
larger nerve that travels to the
brain where they are
interpreted as sound

1. Ultrasonic Frequencies
• These are vibrational
frequencies beyond 20,000
Hz.
Example:
– Dogs can hear sounds as high as 50
000 Hz
– Bats can detect sound as high as 100
000 Hz.
– We can see images of your baby
brother or sister when the OB-gyne
asks your mother or nanay to undergo
ultrasound imaging.

2. Audible
Sound-
•These are
frequencies
ranging from 20
Hz to 20,000 Hz.

3.Infrasonic
Frequencies
•These are low
frequencies
below 20 Hz.

Relate characteristics of
light such as color and
intensity to frequency and
wavelength;
S7LT-IIIf-10
OBJECTIVE

• A form of energy
that made up of
photons.
• It can travel
through
Electromagnetic
wave

What is the difference of Luminous
and Non-luminous?
A luminous object is one
that produces light.
A non-luminous object is
one that reflects light.

Nature of Light
1) Light travels in straight lines
2) Light travels much faster than sound
3) We see things because they reflect light into our
eyes
4) Shadows are formed when light is blocked by an
object

• Light travels in straight lines:
Laser

• Light travelsVERY FAST – around 300 000 km/s or
300 000 000 m/s or 3 𝑥 108
𝑚/𝑠.
At this speed it can
go around the world
8 times in one
second.

• Light travels much faster than sound. For example:
1) Thunder and lightning
start at the same time,
but we will see the
lightning first.
2) When a starting pistol
is fired we see the
smoke first and then
hear the bang.

• We see things because they reflect light into our
eyes:
Homework

• Shadows
Shadows are places where light is “blocked”:
Rays of light

Colour
• White light is not a single colour; it is made up of a
mixture of the seven colours of the rainbow.
We can demonstrate this by
splitting white light with a
prism:
This is how rainbows are
formed: sunlight is “split up”
by raindrops.

The colours of the rainbow:
• Red
• Orange
• Yellow
• Green
• Blue
• Indigo
• Violet

Adding colours
• White light can be split up to make separate colours.
These colours can be added together again.
• The primary colours of light are red, blue and green:
Adding blue and red
makes magenta
(purple)
Adding blue and
green makes cyan
(light blue)
Adding all
three makes
white again
Adding red
and green
makes yellow

Seeing colour
• The colour an object appears depends on the colours of
light it reflects.
For example, a red book only reflects red light:
White
light
Only red light
is reflected

A white hat would reflect all seven colours:
A pair of purple trousers would reflect purple light
(and red and blue, as purple is made up of red and blue):
Purple light
White
light

Using coloured light
• If we look at a coloured object in coloured light
we see something different. For example,
consider a football kit:
White
light
Shorts look blue
Shirt looks red

Infer that conditions
necessary for heat
transfer to occur;
S7LT-IIIh-i-12
OBJECTIVE

Activity 1: KNOW ME!
- Before we start to our next lesson, let us first
answer this activity.
- This activity is in titled “KNOW ME”
- In this activity, you will guess the word that
described by the letters and pictures below.
- I will only choose a student randomly to guess
the word.

At the end of the lesson, you are expected to:
1. Infer the conditions necessary for heat
transfer to occur
2. Illustrate the different methods of Heat
Transfer
3. Realize the importance of heat transfer
to food processing

Activity Rules:
The class will be divided into two groups
Each group will pick a number from the box and the
group that picked the letter A, will be the group that
will perform the task A
And the group that picked the letter B, will perform
the task B
Be extra careful when you perform the activities
below.
Every group will be given five minutes to accomplish
each task.

Any object is said to possess thermal energy due
to its particles whether at rest or in motion.
Thermal Energy

 Heat is an energy that is transferred from
one object to another object due to the
difference in their temperature. It is simply
called as ‘energy in transit’.
 Heat transfer is related to change in
temperature.
Heat

How is heat related to thermal energy?
 Thermal energy refers to the energy
contained within a system that is
responsible for its temperature.
 Heat is the flow of thermal energy.
When energy is transformed, such as
thermal energy, heat is always produced.

 Temperature refers to the
relative hotness or
coldness of an object.
 Instrument used for
measuring and indicating
temperature is called
‘thermometer’.
Temperature

Conduction
takes place between
objects that are in
direct contact with
each other.
Conduction

•Copper
•Iron
•Aluminum
•Steel
•Silver
•Brass
•Lead
Materials that conduct heat well are called
thermal conductors (good conductors)
Example:

•Wood
•Rubber
•Plastic
•Glass
•paper
Whereas materials that conduct heat poorly are
known as thermal insulators (poor conductors)
Examples:

Convection is
the process in which
heat is carried from
place to place by
the bulk movement
of a fluid against its
surroundings.
Convection

Radiation is a method
of heat transfer in the
absence of matter or
through space.
Radiation

Direction: Identify whether the following pictures
show conduction, convection or radiation.
Convection Conduction

Dried fish “Bulad” Smoke fish “Tinapa”

Activity Rules:
- The class will be divided into two groups
- Each group will choose one box in front of
them.
- Both group will perform the task given by
the box.
- Five minutes to accomplish each task.

Multiple choice: Read the questions carefully. Choose
the letter of the best answer.
1.Which conditions necessary for heat transfer to occur.
a. There must be a heat-conducting material between
two bodies for heat transfer
b. There must be a temperature difference between
two bodies for heat transfer
c. The material must be made of metal between two
bodies for heat flow
d. None of the above

2. Heat transfer occurs only in the direction of
______________.
a. Hot object to cold object
b. Cold object to hot object
c. Hot object to hot object
d. Cold object to cold object

3. Which of the following is an example of convection?
a. c.
Boiling water Baking bread in the microwave oven
b. d.
Cooking egg in pan Heating meat from grill burner

4. Which of the following is the case of heat transfer by
radiation?
a. c.
Boiling water Bread in the microwave oven
b. d.
Cooking egg in pan Heating meat from grill burner

5. What method of heat transfer used in
making Tinapa?
a. Conduction
b. Convection
c. Dispersion
d. Radiation

ASSIGNMENT
Answer this question and write in a ½ sheet
of paper.
Scores 1-3
Scores 3-4
Compare and contrast the different method
of heat transfer.

Describe the different
types of charging
processes;
S7LT-IIIj-13
OBJECTIVE

Explain the
importance of earthing
and grouding ;
S7LT-IIIj-14
OBJECTIVE

Third Quarter (3rd) Topics in Science 7!

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