1. A wave is a traveling disturbance that carries energy from one location to another. 2. There are different types of waves including transverse, longitudinal, and surface waves which are distinguished by the direction of particle motion relative to wave propagation. 3. Key wave properties include amplitude, wavelength, frequency, period, and speed.

1. GRADE 7
MODULE 2, QUARTER 3; LESSON 2.1
Teacher’s Guide for Discussion
MA. RACHEL B. ESPINO
Teacher, Science
Buhatan NHS, Sorsogon City

2. • WAVES are
perpendicular
disturbance that
moves away
from a source
and carries
energy with it.

3. 1. A wave is a travelling disturbance.
2. It carries energy from one phase to another.
3. Vibration causes wave motion
4. Waves travel through a medium

4. • The high points of waves are called CRESTS or
PEAKS while the low points are called
TROUGHS.

5. • The AMPLITUDE is the
maximum
displacement from the
rest position. It is the
height of the crest or
depth of a trough
measured from the
normal undisturbed
position.

6. • The WAVELENGTH, λ is
the distance between
two successive crests
or two successive
troughs. It is also equal
to the distance between
any two identical
points on successive
waves.

8. • The FREQUENCY, f is
the number of crests or
troughs that pass a
point per second. This
is equivalent to the
number of complete
waves generated per
second. Frequency is
measured in terms of
hertz (Hz).

9. • The PERIOD, T is the time taken to generate
one complete wave. It is also the time taken
for the crests or any given point on the wave
to move a distance of one wavelength
T = 1/f

10. • The SPEED, v of the wave is
the distance moved by a
wave in one second. Since
the wave crest travels a
distance of one wavelength
in one period, the wave
speed;
v = λ/T or
v = f λ

11. • According to the direction of movement of the
individual particles of the medium relative to
the direction that the waves travel.

12. • Waves in which particles of the medium move
in a direction perpendicular to the direction
that the wave moves.
• Particle motion is PERPENDICULAR to wave
motion.
Example: waves made by rope.

14. • http://youtu.be/UHcse1jJAto?list=PL554315A
A0D2539B8

15. • Waves in which particles of the medium move
in a direction parallel to the direction that the
wave moves.
• Particle motion is PARALLEL to wave motion.
Example: sound wave

17. • http://youtu.be/aguCWnbRETU?list=PL55431
5AA0D2539B8

18. • Waves in which the particles of the medium
undergo a circular motion.
• In a surface wave, it is only the particles at the
surface of the medium that undergo the
circular motion. The motion of particles tend
to decrease as one proceeds further from the
surface.

20. • http://youtu.be/7yPTa8qi5X8?list=PLLOem9gti
iXYsLt2tZVK-mmrR9fJ3FWqV

21. • According to the waves’ ability to transmit
energy through a vacuum (empty space)

22. • A wave that is capable of transmitting energy
through a vacuum.
Example: rays of the sun, light

24. • Waves not capable to transmit energy through
a vacuum.
Example: sound

25. 1. A wave is a travelling disturbance
2. Waves carry energy from one location to
another.
3. Sound waves are examples of transverse
waves
4. Surface waves are waves that occur when
particles of the medium is perpendicular to
the wave of motion.

26. 5. The motion of particles in surface waves tend
to decrease as it proceeds nearer to the
surface.
6. Electromagnetic waves are capable to
transmit energy through a vacuum.
7. Wavelength is equal to the distance between
two identical points on successive waves.
8. The time taken to generate one complete
wave is called amplitude.

27. 9. The low points of a wave are called troughs.
10.The period is the maximum displacement
from the rest position.

29. True or False
1. True
2. True
3. False
4. False
5. False
6. True
7. True
8. False
9. True
10.False
Identification
1. CREST/ PEAK
2. WAVELENGTH
3. AMPLITUDE
4. WAVELENGTH
5. TROUGH