Lesson 2: Properties of waves

Question 1

What is the “amplitude” of a wave?

Answer 1

• The amplitude of a wave is the maximum displacement of a point on
  a wave away from its undisturbed position.

Question 2

What is the wavelength of a wave?

Answer 2

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

Question 3

What is the “frequency” of a wave?

Answer 3

• The frequency of a wave is the number of waves passing a point
  each second.

Question 4

What is the “period” of a wave?

Answer 4

• The time taken for one wave to be completed.

Question 5

What is the unit for Frequency?
What is 1 frequency unit equivalent to?

Answer 5

• Hz.
• 1Hz = 1 wave per second.

Question 6

What is the “wave- speed?”

Answer 6

• The wave speed is the speed at which the energy is transferred (or
  the wave moves) through the medium.

Question 7

What is the equation for calculating wave- speed?

Answer 7

Wave- speed = frequency x wavelength.

Question 8

What is the equation to calculate the frequency of a wave when given the time it takes for 1 wave to complete a cycle?

Answer 8

Frequency = 1/ period.

Question 9

Describe a method to measure the speed of sound waves in air.

Answer 9

1.) Two people stand a certain distance apart.
2.) Person A is holding cymbals, Person B is holding a stopwatch.
3.) Person B starts timing when they see Person A clash the cymbals together.
4.) Person B stops timing when they hear the sound produced by the symbals clashing.
5.) Speed of sound wave = distance between two people/ time taken for sound wave to reach Person B.

Question 10

What are the problems with the the method used to measure the speed of sound waves in air?

Answer 10

1.) Every person has different reaction time –> might not stop the timer AS SOON AS they hear the cymabls.
2.) Time between the cymbals clashing/ hearing the sound is very short.

Question 11

How can we reduce the error of varied reaction times in measuring the speed of sound waves?

Answer 11

• Have a large number of observers with stopwatches to calculate the mean time it takes for the sound wave to reach the other person.

Question 12

How can we reduce the error that comes from the short time between the cymbals clashing and the sound reaching the person in the measuring speed of sound waves method?

Answer 12

• Increase the distance between Person A/B.