4.6.1.2 Properties of Waves

Question 1

Amplitude:

Answer 1

amplitude of a wave is the maximum displacement of a point on a wave away from its undisturbed position/rest point

Question 2

Wavelength:

Answer 2

wavelength on a wave is the distance from one point on a wave to the equivalent point on an adjacent wave

Question 3

Frequency:

Answer 3

the number of waves passing a point each second

Question 4

Time period:

Answer 4

the time taken for one complete wave (length) to completely pass a single point

Question 5

Displacement:

Answer 5

• distance from rest point of wave
• direction of wave

Question 6

How do you calculate the period?

Answer 6

T = 1/f
Period = 1/frequency

Question 7

How do you calculate wave speed?

Answer 7

Wave speed = frequency x wavelength

v=λf

Question 8

Wave speed:

Answer 8

the speed at which energy is transferred (or the wave moves through a medium)

Question 9

Method to measure speed of sound waves in air:

Answer 9

1. 2 people separated by 500m
2. Person A has symbols and Person B has a timer
3. Person B starts timer when they see person A clash cymbals together
4. Person B stops timer when they hear the sound the cymbals make
5. Calculate the speed of sound in the air by using formula : speed = distance/time

OR

1. Have two microphones connected to a data logger at a large distance apart
2. Record the time difference between a sound passing one to the other
3. Calculate the speed of sound in the air by using formula : speed = distance/time

Question 10

Problems with method for measuring speed of sound waves in air and how those problems can be solved/reduced:

Answer 10

• every person has different reaction time e.g takes a fraction of section between seeing cymbal ad starting timer also takes fraction of a second between hearing sound and stopping the timer
  
  • can reduce this error by having a large number of observers with timers
  • take all of the results then discard any that are anomalous
  • then calculate a mean value
• time between seeing cymbals clash and hearing sound is very short - makes it very difficult to press timer at correct times
  
  • can reduce problem by increasing distance between person A and person B
  • the longer the distance the longer the time
  • this makes it easier to start and stop the timer at correct times