Chapter 1 Waves

CHAPTER 1 WAVES

1.1Understanding Waves ( ……………/ 25 X 100 % = ……………… )

Learning Outcomes

A student is able to :

Describe what is meant by wave motion.
Recognise that waves transfer energy without transferring matter.
Compare transverse and longitudinal waves and give examples of each.
State what is meant by a wavefront.
State the direction of propagation of waves in relation to wavefronts
.define

amplitude
period,
frequency,
wavelength,
wave speed.

Sketch and interpret a displacement-time graph for a wave.
Sketch and interpret a displacement-distance graph for a wave,
Clarify the relationship between speed, wavelength and frequency
.Solve problems involving speed, wavelength and frequency.
Describe damping in a oscillating system.
Describe resonance in a oscillating system.

1. Fill in the blanks by choosing a words given.

parallel / perpendicular / rarefraction / trough / compression / crest

a) The wave that travels along the spring consists of a series

(1)…………………..and(2)………………………….

b) A longitudinal wave is a wave in which the vibration of the medium

is (3)…………………….to the direction of propagation of the wave.

c) A transverse wave is produced when the vibration of the medium is

(4)………………….to the direction of propagation of wave.

d) The wavelength is the distance between two adjacent

(5)…………………………or two adjacent(6)………………………..

2. Match the following terms with the meaning given.

Terms / Meaning
Wavefront / 1 / (7) / The displacement of a crest or a trough from the equilibrium position of a wave.
Wavelength / 2 / (8) / The number of waves produced by a source in one unit time.
Amplitude / 3 / (9) / The distance between two adjacent points of the same phase on wave.
Frequency / 4 / (10) / Lines joining all points of the same phase.
Wavespeed / 5 / (11) / The measurement of how a crest is moving from a fixed point.
Period / 6 / (12) / Time taken for an oscillation to complete one cycle.

Complete the sentence and chart given below with suitable words.

a)In a damping oscillation,(13)...... and (14)……………….…

remain constant while (15)………... decreases.

(16,17,18,19)

b)State two causes of damping in an oscillating system:

…………………………………(20)

…………………………………(21)

Figure shows the displacement-distance and displacement –time graphs of an oscillating system.

From the graphs determine the…….

a)Period :…………………………………….(22)

b)Frequency :……………………………………..(23)

c)Wavelength :………………………………….…(24)

d)Speed of the waves.:……………………………………(25)

1.2 : Analysing reflection of waves ( ……………/ 10 X 100 % = ………… )

Learning Outcomes

A student is able to :

Describe reflection of waves in terms of the angle of incidence, angle of reflection,

wavelength, frequency, speed and direction of propagation.

Draw a diagram to show reflection of waves.

Diagram 1.1 and 1.2 shows water waves and sound waves propagating towards a

reflector.

Diagram 1.1

Diagram 1.2

a ) ( i) What is meant by reflected waves?

……………………………………………………………………………………(1)

( ii) Complete the diagrams 1.1 and 1.2 to show the phenomena of reflection of

waves.

(2),(3),(4),(5)

(iii) With reference to diagram 1.1 and 1.2,compare the incident and reflected angle,

wavelenght, frequency, speed and direction of propagation of the reflected

wave with the incident wave. Complete the table with a suitable word..

Angle of reflection……………………..the angle of incidence (6)
Wavelength / remains unchanged
Frequency / ……………………………….(7)
Speed / ……………………………….(8)
Direction of the
propagation / ……………………………….(9)

(iv) State the principle of the reflection of waves.

…………………………………………………………………………………….(10)

1.3 Analysing refraction of waves ( ……………/ 12 X 100 % = ……………… )

Learning Outcomes

A student is able to :

describe refraction of waves in terms angle of incidence, angle of refraction,

wavelength, frequency , speed and direction of propagation.

Draw a diagram to show refraction of waves.

1. Figure below shows the plane waves approaching a convex-shaped shallow area.

(a) Complete the diagram by drawing the wavefronts of the waves entering the shallow

area. Label clearly the wavelength in a shallow area with λ1 and in deep area with

λ2. (1),(2),(3)

(b) Complete the table below, to show what happen to wavelength, frequency, speed

and direction of the propagation of wave after the phenomena of refraction.

Wavelength / (4)
Frequency / (5)
Speed / (6)
Direction of the
propagation / (7)

2. Diagram below shows the phenomena of refraction of water wave of the sea water

1. Why are the speed and wavelength of waves in the middle of the sea almost

uniform?

……………………………………………………………………………….(8)

2. Why do the distances between the wavefronts decrease as the waves approach the

beach?

…………………………………………………………………………………(9)

3. Why is the water in the bay stationary compared to the water at the cape?

i.………………………………………………………………………………………

ii………………………………………………………………………………………

iii……………………………………………………………………………………..

(10),(11),(12)

1.4 Analysing diffraction of waves ( …………… / 18 X 100 % = ……………. )

Learning Outcomes

A student is able to

describe diffraction of waves in terms of wavelength, frequency, speed,

direction of propagation and shape of waves,

draw a diagram to show diffraction of waves.

1.Diagram 1 shows a listener who is able to hear the sound of the radio behind the wall of

a building.

Diagram 1.

Name the wave phenomenon shown in the diagram above ______(1)

2. ______(2) of waves is a phenomenon in which waves ______(3) as theypass through a ______(4) or round an ______(5).

3. Diagram 3a and 3b shows water waves passing through a narrow gap and a wider gap respectively.

(6) (7)

Diagram 3a Diagram 3b

(a) Complete diagrams3a and 3b above to show the wave pattern after passing through

the gaps.

(b) Based on your answer in (a) state the relationship between the wavelength , size of the

gaps and the wave pattern formed.

______

(8),(9)

(i)wavelength :______(10)

(ii)Frequency :______(11)

(iii)Speed :______(12)

(iv)Amplitude :______(13)

Diagram 4 shows light from a laser pen is diffracted if it passes through a narrow

slit comparable in size to its wavelength.

(a)In the space below , draw and label the diffraction pattern of light through a

narrow slit.

(14)

(b)As the light passes through the single slit , it is diffracted to produce a wide

______(15) fringe at the centre.

(c)After diffraction , interference also occur to produce alternate bright and

______(16) fringes at the side of the middle bright fringe.

(d)The bright fringe is caused by ______(17) interference and the dark

fringe is produced by ______(18) interference.

1.5 Interference of Waves ( ……..……./ 20 x 100 % = ..…………. )

Learning Outcomes

A student is able to :

state the principle of superposition
explain the interference of waves
draw interference patterns
interpret interference patterns
apply the following formula in problem solving

State the Principle of Superposition of waves.

(1)

Interference is the superposition of two coherent waves. Two waves are

coherent if they have the same wavelength , same ______(2) and constant ______(3).

Complete the table below

(a) Superposition
of two crests / / Constructive interference
(b) Superposition
of two troughs / (4) / (5)
(c) Superposition
of a crest and a trough / (6) / (7)

4. Diagram 4 shows an interference pattern produced by two coherent sources P and Q

P Q

Diagram 4

In the diagram above , draw and label one antinodal and one nodal line.

(8), (9)

5. Complete the table below to compare sound and light waves.

Light / Sound
Constructive interference / Bright fringes / (10)
Destructive
interference / (11) / (12)

6.Diagram 6 shows an experiment to study the interference of light waves.

Diagram 6

(a)What is meant by monochromatic light ?

______(13)

(b)In the boxes above , label a , x and D where

a = distance______(14)

x = distance______(15)

D = distance ______(16)

(c ) What is the relationship between a, x, D and λ?

(17)

(d ) Calculate the wavelength of light used if a = 0. 2 mm , x = 3 mm , and D is 4 m.

[ ] (18)

7Two loud speakers placed 2 m apart are connected to an audio signal generator that is adjusted to produce sound waves of frequency 550 Hz. The detection of loud and soft sounds as a person moves along a line is at 4.0 m from the loudspeakers. The distance between 2 consecutive loud sounds is 0.5 m.

Calculate the

(a)Wavelength of the sound waves. (19)

(b)speed of the sound waves. (20)

1.6 Sound Waves ( ……………./ 20 x 100 % = ……………. % )

Learning Outcomes

A student is able to :

describe sound waves
explain how the loudness relates to amplitude.
explain how the pitch relates to frequency.
describe applications of reflection of sound waves.
calculate distances using the reflection of sound waves.

1. Fill in the blanks.

(a) Sound waves are ______(1) waves .

(b) Sound waves are produced when a vibrating object causes air molecules around

it to ______(2) and producing a series of ______(3) and

______(4)

2. Diagram 2 shows a tuning fork producing sound waves.

Diagram 2

(a)Label the wavelength (5)

(b)Label areas of compression (6) and rarefaction (7)

3. Complete the concept map below.

(8),(9),(10),(11),(12),(13)

4. Diagram 4 shows a submarine transmitting ultrasonic waves directed at a big rock on the sea bed. After sometime, the submarine detects the wave again.

(a)State the wave phenomenon involved.

______(14)

(b)State 2 reasons why the submarine used ultrasonic wave but not ordinary sound wave.

1...... (15)

2...... (16)

(c)Calculate the distance of the submarine from the big rock if the submarine

detects the second wave after 1.5 seconds. [Velocity of ultrasonic wave =

1560 m s-1]

(17),(18)

(d)State 2 other applications of sound waves.

1. …………………………………………………………………………………………..

2. ……………………………………………………………………………………………

(19),(20)

1.7 Analysing electromagnetic spectrum ( ……..…….. / 20 x 100 % = …………..…)

Learning Outcomes

1. Diagram 1 show the electromagnetic spectrum. Write the names of the electromagnetic

waves in the boxes provided.

Diagram 1

(1),(2),(3)

2. Electromagnetic waves are ______(4) waves ,consisting of______(5) fields and

netic fields vibrating ______(6) to each other.

3. ______(7) has the highest frequency and the ______(8) wavelength.

4. List 4 properties of electromagnetic waves.

(i) ______

(II) ______

(III)______

(IV) ______

(9),(10),(11),(12)

5. Diagram 2 show electromagnetic waves. Match the correct source by drawing lines from

the boxes to the respective sources.

(13),(14),(15),(16)

6. Name the electromagnetic wave which is used in the following appliance:

(i) FM Radio ______(17)

(ii) Oven ______(18)

(iii) Communication Satellite______(19)

(iv) Taking pictures of bones______(20)