Q1. A pipe open only at one end has a fundamental frequency of 241 Hz. A second pipe, initially identical to the first pipe, is shortened by cutting off the portion of the open end. At the present, when both pipes vibrate at their fundamental frequencies, a beat frequency of 13 Hz is heard. How many centimeters were cut off the end of the second pipe? The speed of sound is 343 m/s.
Q2. A diver 50 m deep in 10 degrees Celsius fresh water exhales a 1.2 cm diameter bubble. What is the bubble's diameter just as it reaches the surface of the lake, where the water temperature is 35 degrees Celsius? Suppose that the air bubble is always in thermal equilibrium with the surrounding water.