Waves Practice — Wave Equation, Sound and Doppler Effect
10 problems · instant feedback · full explanations
Nearly every wave problem runs through v = fλ. Identify which two quantities you know, solve for the third, and keep frequency and wavelength straight — one is 'how often', the other is 'how long'.
Q1.
A sound wave travels at 340 m/s with frequency 170 Hz. What is its wavelength?
Multiple choice · Easy
Q2.
A tuning fork produces a 440 Hz tone with wavelength 0.78 m in air. What is the speed of sound?
Numerical answer (m/s) · Easy
Q3.
An observer counts 3 wave crests passing per second. If the wavelength is 2 m, what is the wave speed?
Numerical answer (m/s) · Medium
Q4.
Sound traveling through air is which type of wave?
Multiple choice · Medium
Q5.
True or false: sound can travel through a vacuum.
True / False · Easy
Q6.
An ambulance drives toward you with its siren on. Why does the pitch sound higher than when it is parked?
Multiple choice · Medium
Q7.
What is the period of a simple pendulum with length 1.0 m? (g = 9.8 m/s²)
Numerical answer (s) · Medium
Q8.
A 0.6 m guitar string has wave speed 120 m/s. What is the frequency of its fundamental (first harmonic) standing wave?
Numerical answer (Hz) · Hard
Q9.
The speed of a wave stays constant while its frequency doubles. What happens to its wavelength?
Multiple choice · Hard
Q10.
True or false: in a transverse wave, the medium's particles move parallel to the direction the wave travels.
True / False · Medium