Please help me with these questions

Video resource 1. https:[[wmm.youtube.com[watch?v =eaeyI|Asto Lab Discussion Questions: Open the YouTube clip above and answer the following questions 1. Why does the researcher hold the tuning fork above the pvc tube? 2. Why does the researcher move the tube in and out of the water? and why does she move the tuning fork along with the tube (notice she keeps it at the very opening of the pvc tube the entire time). 3. What does it mean when the sound is loudest? 4. What is the relationship between the tube when the sound is the loudest and the tuning fork? 5. What would happen if the experimenter used a tuning fork that was a different frequency? Explain