Hello I'm confused with all this question. Thank you

Review Worksheet 1. A train approaching a crossing sounds its horn with a frequency of 750 Hz. Matt, standing at a distance down the tracks. measures the frequency of the whistle to be 675 Hz as the train moves away from him. If the air temperature is 25C. nd the speed of the train in kmfh. (VI: 138.7 km/h) Lukas wants to be a piano tuner when he grows up. He knows that a steel piano string that is 15.0 cm long produces a sound of 3000 Hz, which is slightly at (low) while it is under a tension of 125 N. What must its tension need to be changed to in order to produce the proper musical note high G (3136 Hz)? (T2 = 136.59N) 3. Balkaran plays the tuba in the school band. A tuba can be considered as an air column open at both ends. When straightened out, it is approximately 3.5 m in length. The instrument is played in a room where the air temperature is 25C. Ignoring and corrections. what is the lowest frequency the tuba can play at this length. (fl = 49.5 Hz) Holy Trinity has moved to a new facility. There is a gym 200 m long. I _. ' I 4' ' J go When the coach. standing at one end, blows his whistle, the reverberation ) \\9 time (the time for the echoing of the sound to stop) is 8.5 5. Approximately '* how many times does the sound reflect from the far wall before it becomes too faint to be heard? Assume the temperature in the gym is 20 C. (7 times) A 5. Gwen wants to sing in the Holy Trinity Choir. A vocal tract acts as an air column closed at one end. Gwen's vocal tract is 25.0 cm long and is vibrating in the second overtone. if the speed of sound is 352 m/s, what frequency is Gwen producing? (1.76 x 103 Hz) Ethan is going to tune up his guitar. A guitar string 0.50 m long and with a tension of 200N has a fundamental frequency of 4OOHz. He shortens the length to 0.4 m and he increases the tension to SOON. What is the new fundamental frequency? (f2 = 612.37 Hz) 7. Aidan is training for the Olympics. He is swimming across Lake Ontario when he spots Tristan falling from the sky. (Probably still testing out those MC hammer pants!) He hears the impact twice, rst through the water with one ear and then through the air with the other ear 1.0 5 later. How far away did the impact occur? (speed of sound = 340mls in air. speed of sound in water 1400m/s). (d = 448 m) ;