1) A person stands at a point 300m in front of the face of a sheer cliff, If the person shouts, how much time will elapse before an echo is heard?
2) The sound level measured in a room by a person watching a movie in a home theater system varies from 65 dB during a quiet part to 95dB during a loud part. Approximately how many times louder is the latter sound?
3) What are the frequencies of the first four harmonics of middle C(261.6Hz)?