Waves and Sounds | 6

Question 1

Speed of wave (formula)

Answer 1

F x λ

Question 2

Types of waves

Answer 2

Transverse | Longitudanal

Question 3

What are the parts of the 2 types of waves

Answer 3

Transverse - Crest , through

Longitudinal - Compression , rarefaction

Particles don’t move , only the energy of sound is carried from one place to another

Question 4

Is sound a Transverse wave

Answer 4

sound waves are longitudinal , but we represent them as transverse

Question 5

Wavelength

Answer 5

Also know as lambda , measured in cm / M

From one part till when it is repeated

(if it starts on the crest , then it will end at the second crest and at the same position)

Question 6

Amplitude

Answer 6

Height / depth of the crest / through

Maximum displacement from the mean position

Question 7

Frequency

Answer 7

Number of waves that pass a point in a 1 second

Hz

Question 8

Time period

Answer 8

Time taken for 1 complete wave to pass a point

Question 9

Reflection

Answer 9

Bouncing back of a wave from a surface

Question 10

Refraction

Answer 10

When a wave enters a new medium

Under goes a change in SPEED + DIRECTION

(in water waves , refraction also happens when there is change in water depth)

Question 11

Explain speed and direction in refraction

Answer 11

Deep water - waves move faster

when wave enters a new medium at a angle it bends

(NO change in frequency)

Denser Medium - Speed ↓
Wavelength ↓
Bends towards normal

Rarer Medium - Speed ↑
Wavelength ↑
Bends away normal

(Frequency stays the same no matter what)

Question 12

Diffraction

Answer 12

Spreading of waves through a narrow slit

Bending of waves around corners

Narrow = Wave diffraction ↑

Wide = Wave Diffraction ↓

Ripple tank is used to see wave effects with water

Question 13

Wave theory

Answer 13

Wave fronts , wavelets can be used to understand and show reflection , refraction and diffraction (propagation of energy)

Question 14

Wave front

Answer 14

Imaginary line that joins all points that are in the same phase of motion

Distance between 2 wave fronts is the same as one wavelength

Question 15

Wavelet

Answer 15

Representation of energy carried by each point in a wave

Question 16

Properties of sound

Answer 16

Form Of energy

Produced by vibrations

Travels as longitudinal waves

Needs a medium to travel through

Fastest in solids , unable to travel in vaccum

speed depends on material , density , temp

Question 17

Reflection (sound)

Answer 17

Echo (parking sensors) , (Recording studios use materials that absorb echo)

Question 18

Echo sounder

Answer 18

Finds Depth of water using pulses of sounds onto the seabed

(electronic tape measure is same but used for cliffs and so is radar but it uses microwaves to detect aircrafts or shis)

Question 19

Echo sounder formula

Answer 19

1/2st = d

speed of sound in water = 1500 m/s

Question 20

Characteristics of sound waves

Answer 20

more the frequency , more the pitch

higher the amplitude , louder the sound

Question 21

how to display a sound wave

Answer 21

connect mic with oscilloscope

Question 22

Ultrasound uses

Answer 22

20000 Hz (outside hearing range of 20 - 20000 Hz)

Used in echo sounding

Used in cleaning dust of machinery

used to break kidney stones

Used to scan babies (less danjer than x - ray , picks up pulses from baby and forms computerized image)

Question 23

How can you use ultra sound to find flaws in metals

Answer 23

Use a ultrasound transmitter and receiver , when it sends the ultra sound , it can detect if the pulse was reflected from a flaw