Activities

Note that the velocities are specified in terms of the wave velocity, where positive is directed right. Thus, a source speed of 1 means that the observer moves at the speed of the waves.

1. Start with the source at rest and the observer at rest, and observe the pattern produced when you press the Play button. Describe the pattern also in terms of the relationship of f and f'. Hint: f = f'
2. Now, keep the source at rest, and give the observer an initial velocity. Explore how the frequency of the waves reaching the observer changes as you vary the observer's velocity. Does this depend on whether the observer is moving toward the source or away from the source? Does the motion of the observer effectively change the speed of the waves or the wavelength?
3. Now, keep the observer at rest and explore the effect of the motion of the source. How does the frequency of the waves reaching the observer depend on the source velocity? Does the frequency shift depend on whether the motion of the source is toward or away from the observer? Does the motion of the source effectively change the speed of the waves or the wavelength?
4. Now that you are more familiar with the simulations terms, objects and quantities, design and experiment to deduce the relationship between f' and f. Hint: a table with your inquiry quantities will be useful in your self directed science discovery.
5. What happens when the source travels at the same speed of the waves? Hint: your explanation should include/ make reference to terms like Mach, Shockwave, Sound Barrier and Sonic Boom.
6. What happens when the source travels faster than the wave speed? Hint: your explanation should include terms/make reference to Mach, Shockwave and SuperSonic.