Describing waves

4 marks · Normal

The graph below shows the displacement of a point in a wave against time.

Wave displacement vs time

(a)

State the amplitude of the wave.

[1 mark]

(b)

Determine the time period of the wave.

[2 marks]

(c)

Calculate the frequency.

[1 mark]

Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.

Show answer

(a) 5 cm

(b) 2 s

Show mark scheme and worked solution

Marking points

B1 (a) · 1 mark · States amplitude as 5 cm (max displacement on y-axis).

M1 (b) · 1 mark · Measures period as time for one full cycle (e.g., 0 to 2 seconds).

A1 (b) · 1 mark · Gives correct time period: 2 s.

B2 (c) · 1 mark · Calculates frequency: 1/period = 0.5 Hz.

Worked solution

a) Amplitude is the maximum positive or negative displacement: 5 cm.

b) From t = 0 to t = 2 s is one cycle, so period T = 2 s.