## Essential University Physics: Volume 1 (3rd Edition)

(a) we know that angular frequency can be determined as $\omega=2\pi f$ We plug in the known values to obtain: $\omega=2\pi (4.86\times 10^6)$ $\omega=3.05\times 10^7\frac{rad}{s}$ (b) We can find the wave number as $k=\frac{2\pi}{\lambda}$ We plug in the known values to obtain: $k=\frac{2\pi}{0.313\times 10^{-3}}$ $k=2\times 10^4m^{-1}$ (c) We know that $v=f\lambda$ We plug in the known values to obtain: $v=4.86\times 10^6\times 0.313\times ^{-3}$ $v=1520\frac{m}{s}$