4.2.1 Answers

A:the wave vector is 2.62 /m

B: the phase velocity is 1.23x10^3 m/s to the right, assuming the least possible displacement to the right during the elapsed time

C: and the angular frequency is 3.2x10^12 /s

D: If the wave has moved an additional wavelength to the right, then the phase velocity is 3.0x10^3 m/s and the angular frequency becomes 7.9x10^12 /s. Other answers are possible as well, including negative as well as positive.