How to solve these two questions of sound?

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Question: The speed of sound in air on a certain day is 340 m/s. A tube is partially submerged in water and a note with a frequency of 972 Hz is played through headphones at the end of the tube (Figure 1). It is observed that the rst resonance occurs when L = 7.58 cm. Figure 1: Diagrammatic representation of a set of headphones emitting a note through the end of a tube that is partially submerged in a container of water. When the length of the unsubmerged portion of the tube is L cm, the rst resonance is observed. Part 1) How large are the end effects? e cm Part 2) What length of tube should be above the water to hear the 9" harmonic? L = cm Part 3) If the frequency of the tone is now increased to 1096 Hz, what length of pipe is now needed to hear the first resonance? X = cmQuestion: A killer whale moving with a speed of 13.189 m/s chases a seal swimming at 3.649 m/s through the ocean. The killer whale emits a sound with a frequency of 6.187 kHz. The speed of sound in the ocean is 1473 m/s. Part 1) What frequency does the seal detect coming from the killer whale? Part 2) The signal is reected off the seal back to the killer whale. What frequency does the killer whale detect? Part 3) If the killer whale and seal are initially 203.8 m apart, how long until the killer whale catches up to the seal