D Question 3 2 pts What is the frequency of the third harmonics of a standing wave in a 2 m long organ pipe open at both ends? The fundamental frequency is 85 Hz. O:85 Hz 170 Hz 255 Hz O 340 Hz. O 382 Hz D Question 4 3 pts In the physics lab a string with a fixed frequency vibrator at one end is subjected to varying tensions. When the tension is 20 N, a resonance with 3 antinodes results. What tension would cause a resonance with 2 antinodes in this string? O 30 N O 45 N O BON O BON O: 13 N