Wavelength and frequency
4 marks · NormalA student is investigating waves in a rope by creating pulses at one end and measuring their properties.
State the equation that links wave speed, frequency, and wavelength.
The wave in the rope has a frequency of 5 Hz and a wavelength of 0.8 m. Calculate the speed of the wave.
State the unit of frequency.
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) v = f × λ
(b) 4 m/s
(c) Hertz (Hz)
Common mistakes: incorrect rearrangement; using wrong unit
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Correctly states v = f × λ or equivalent.
M1 (b) · 1 mark · Substitutes frequency and wavelength into v = f × λ. (follow-through)
A1 (b) · 1 mark · Calculates correct value: 4 m/s. (follow-through)
B1 (c) · 1 mark · Correctly states 'hertz' or 'Hz'.
Worked solution
a) The equation linking wave speed, frequency, and wavelength is:
b) Use v = f × λ.
c) The SI unit of frequency is hertz (Hz).