Properties of Waves (Edexcel International A Level Physics)

The graph below shows a travelling wave.

Determine:

(i) The amplitude A of the wave in metres (m)

(ii) The frequency f of the wave in hertz (Hz)

Answer:

Part (i)

Identify the amplitude A of the wave on the graph 

• The amplitude is defined as the maximum displacement from the equilibrium position (x = 0)

  

• The amplitude must be converted from centimetres (cm) into metres (m)

A = 0.1 m

Part (ii)

Calculate the frequency of the wave

Step 1: Identify the period T of the wave on the graph 

• The period is defined as the time taken for one complete oscillation to occur

• The period must be converted from milliseconds (ms) into seconds (s)

T = 1 × 10^–3 s

Step 2: Write down the relationship between the frequency f and the period T 

f = 

Step 3: Substitute the value of the period determined in Step 1

f = 

f = 1000 Hz

Every question about waves uses the vocabulary on this page. Many questions start by asking you to define one of them.

So your job is to learn the definitions to the point where you have them memorised.