A. refraction B. reflection C. resonance D. the Doppler effect 17. B. surface C. transverse D. standing wave 18. As a supersonic aircraft passes, a high-amplitude wave trails behind it as shown. A. transverse B. longitudinal C. surface D. token 20. A. speed B. amplitude C. frequency D. loudness 21.
Nothing vibrates in space.
Sound waves require a medium. Two organ pipes of equal length are played at their lowest resonating frequencies. Both pipes will sound the same frequency. Two tuning forks are struck and an oscillating tone that alternates between loud and soft twice a second is heard. A. increases B. decreases C. stays the same 31.