A speaker vibrates at a frequency of 680 Hz and emits a sound wave. The figure shows the compressions and rarefactions of the air and the displacement of the air particles from the equilibrium position as a function of the distance from the speaker in zero seconds.
What is the displacement of the particles from the equilibrium position in 1 ms at a distance of 1.3 m from the speaker? The velocity of the wave in the air is 340 
, and the amplitude from the equilibrium position is 10 nm.
