2.5 Waves & Motion

Question 1

What is a mechainical wave

Answer 1

An oscillation of Matter

Question 2

Mechanical waves cannot exist in

Answer 2

A Vacuum

Question 3

2 types of mechanical waves, what are they?

Answer 3

Transverse & Longitudinal

Question 4

What is a Transverse wave?

Answer 4

the displacement of the medium is perpendicular to the direction of propagation of the wave. The highest point of the wave is called the crest, and lowest point is called the trough.

Question 5

What is a Longitudinal Wave

Answer 5

the displacement of the medium is parallel to the propagation of the wave.

Question 6

When the Particles in a wave are close together what is it called?

Answer 6

Compression

Question 7

When the Particles in a wave are spread apart what is it called?

Answer 7

Rarefraction (Expansion)

Question 8

What is a Sine wave?

Answer 8

A sine wave has a waveform that is periodic as it repeats itself at standard intervals in a specific manner and with a constant amplitude.

Question 9

Periodic Time =

Answer 9

Time taken to complete 1 oscillation

Question 10

Frequency =

Answer 10

Number of complete oscillation in 1 second

Question 11

Formula for wavelength

Answer 11

wavelength = wave speed / frequency
therefore
**wave speed m/s = frequency hz x wave length **
**Frequency hz = wave speed m/s / wave length

Question 12

What is Interference Phenomena?

Answer 12

Wave interference is the phenomenon that occurs when two waves meet while travelling along the same medium, and form a resultant wave of greater, lower, or the same amplitude.

2 sine waves of amplitude 1 overlap each other the resulting shape would be an upward direction with an amplitude of 2 units

Question 13

What is a standing wave known as?

Answer 13

Interference

Question 14

Value of Speed of sound in Air, Water & Steel?

Answer 14

• Air = 343 m/s
• Water = 1500 m/s
• Bar of steel = 5000 m/s

Question 15

What happens to the speed of sound in higher temperatures

Answer 15

Faster the speed of sound

Question 16

Formula for speed of sound

Answer 16

c = 20 x sq route T
* c - speed of sound in air (m/s)
* T = Temp (K)

Question 17

Define Mach Number

Answer 17

The Mach number describes the ratio of the speed of an aircraft in relation to the speed of sound.

Question 18

Formula for Mach Number

Answer 18

M = v / c
* M = Mach Number
* v = Speed of Object (m/s)
* c = speed of sound (m/s)

Question 19

Sound cannot be transmitted through

Answer 19

A Vacuum

Question 20

Pitch depends on

Answer 20

The frequency of sound

Question 21

The greater the frequency?

Answer 21

the higher the pitch and vice versa.

Question 22

3 characteristics of sound

Answer 22

• Loudness
• Pitch
• Quality

Question 23

Loudness depends on

Answer 23

The Amplitude

Question 24

Pitch depends on

Answer 24

The frequency

Question 25

Quality depends on

Answer 25

The Waveform

Question 26

Sound is normally a combination of frequencies, What are they?

Answer 26

The lowest is called the fundamental frequency and the others are called overtones.

Question 27

If the source of a sound moves towards you

Answer 27

the frequency of the sound will appear higher and if it moves away the frequency appears lower. This is called the doppler effect