P11- wave properties 📻

Question 1

What is wave ?

Answer 1

• a wave, is a vibration or disturbance transmitted through a medium [a material] or through space, that transfers energy from one place to another, without transferring matter

Question 2

What are the two types of waves ?

Answer 2

• the two types of waves are:
• transverse
• and, longitudinal waves

Question 3

• Fill in the gaps: all waves ________ energy from one place to another, and it is the wave that moves not the ______ [such as water or the air]

Answer 3

• all waves transfer energy from one place to another, and it is the wave that moves not the matter [such as water or the air]

Question 4

What is a transverse wave ?

Answer 4

• a transverse wave, is a wave where the vibration is perpendicular [at right angles] to the direction of energy transfer
• [think t for transverse, since the direction of the wave is perpendicular to the oscillation, which looks like a t]

Question 5

What’s a longitudinal wave ?

Answer 5

• a longitudinal wave, is a wave in which the vibrations are parallel to the energy transfer
• [think ’l’ for longitudinal, as the direction of the wave is parallel to the oscillation, and looks like an I]

Question 6

What are the features of transverse waves ?

Answer 6

• transverse waves have oscillations that are up and down; their direction of energy transfer is perpendicular
• and unlike longitudinal waves, not all transverse waves require a medium [meaning transverse waves can travel in a vaccum]

Question 7

What are the features of longitudinal waves ?

Answer 7

• unlike transverse waves, longitudinal waves oscillations are parallel to the direction of energy transfer
• and, all longitudinal waves require a medium to travel in [for example, water waves require a liquid medium: water, to travel in]

Question 8

What are oscillations ?

Answer 8

• oscillations, are repeated and regular fluctuations, above and below the same position [of a wave]

Question 9

Easy: How can sound waves travel through the air ?

Answer 9

• sound waves will travel, as the air particles [in the air] move from side to side

Question 10

What are longitudinal waves composed of ?

Answer 10

• longitudinal waves are composed of compressions or rarefractions.
• there are compressions [regions or areas, where the crest between waves are close together]
• ; there are also rarefactions [regions or areas, where the crest bewteen waves are far apart, and the air particles are spaced out]

Question 11

What are some examples of longitudinal and transverse waves ?

Answer 11

• examples of transverse waves are:
• ripples on the surface of the water, which transfer kinetic energy
• ; examples of longitudal waves are:
• sound waves travelling the air

Question 12

What is the amplitude of a wave ?

Answer 12

• the amplitude of a wave, is the maximum displacement [crest or trough] of a point on a wave, away from its undisturbed position [the midpoint]
• [in simpler terms, the amplitude is the furthest point the wave vibrates from its undisturbed position]

Question 13

What does wavelength mean ?

Answer 13

• the wavelength of a wave, is the distance from a point on one wave to the equivalent point on the adjacent wave

[distance between a point on one wave to the same point on the next wave]

Question 14

How can the wave length of longitudinal waves, be measured ?

Answer 14

• the wavelength of longitudal waves can be measured:
• by measuring from one compression to the next compression, and then vice versa from one rarefaction to the next rarefaction.

Question 15

What is the frequency ?

Answer 15

• the frequency, is the number of waves passing a point each second

Question 16

How can the frequency of a wave be calculated ?

Answer 16

• the frequency of a wave can be calculated by counting the number of waves

Question 17

What is the period of a wave ?

Answer 17

• the period of a wave, is the time [in seconds] for one wave to pass a point

Question 18

What does wave speed mean ?

Answer 18

• wave speed, is the speed at which the waves moves through the medium [meaning, the speed at which energy is transferred]

Question 19

Describe a method to measure the speed of sound in air ⏱️

Answer 19

• two people [person a and b]are separated by a distance of 500m
• person a will hold a pair of cymbals, and person b will hold a timer
• person b will start the timer, when they see person a clash the pairs of cymbals together; person b will stop timing when they see the sound of the cymbals crashing.
• *the speed of the sound waves can then be calculated by: v= s/t