2. Amit, Emad, and Joshua are holding a tuning fork oscillating at 256 Hz. They walk towards a wall at a constant speed of 1.33 m/s. Use v = 344 m /s for the speed of sound. a) What is the apparent frequency that they hear (reflected from the wall)? (5 pts) b) What beat frequency do they observe between the tuning fork and its echo? (5 pts) c) How fast must they walk away from the wall to observe a beat frequency of 5 Hz? (5 pts)