Waves
4 marks · EasyA sound wave travels through air at a speed of 340 m/s.
If the frequency of the sound wave is 680 Hz, calculate its wavelength.
Write down the equation you used for this calculation.
Give one feature of a sound wave you can see displayed on an oscilloscope.
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) 0.50 m
(b) wave speed = frequency × wavelength OR v = f × λ
(c) Amplitude or frequency (period)
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Correct use/substitution in v = f × λ or rearranged formula. (follow-through)
A1 (a) · 1 mark · Correct answer: 0.50 m (allow 2 significant figures or better). (follow-through)
B1 (b) · 1 mark · States correct wave equation: v = f × λ.
B1 (c) · 1 mark · Names a feature visible on an oscilloscope (amplitude, frequency, period, wavelength).
Worked solution
a) Use the equation v = f × λ. Rearranged: λ = v / f = 340 m/s ÷ 680 Hz = 0.50 m
b) The equation is v = f × λ.
c) Features like amplitude (how tall the waves are), frequency (how many per second), or period can be seen on an oscilloscope.