A tuning fork vibrating with a frequency of 512 Hz is kept close to the open end of a tube filled with water (figure). The water level in the tube is gradually lowered. When the water level is 17 cm below the open end, the maximum intensity of sound is heard. If the room temperature is , calculate;
1. Speed of sound in air at room temperature.
2. Speed of sound in air at .
3. If the water in the tube is replaced with mercury, will there be any difference in your observations?