An air column of length L= 1.25 sustains a standing wave with a displacement antinode (pressure node) at one end and a displacement node (pressure antinode) at the opposite end. In between the two ends exist two pressure nodes. What is the harmonic index n of this standing wave?

The astronauts on the space shuttle flights experienced an acceleration of 29 m/s2 (about 3 "g's") during lift-off. what upward force must the astronaut's seat apply to the astronaut in order to cause this acceleration? assume the astronaut's mass is 70 kg, and compute this force when the acceleration is near the earth's surface so their weight equals latex: mg m g .