1. What is the frequency, in hertz, that corresponds to each of these periods: (a) 0.10 s, (b) 5 s, (c)  s? 2. The nearest star beyond the Sun is Alpha Centauri, which is  m away. If we were to...

1. What is the frequency, in hertz, that corresponds to each of these periods: (a) 0.10 s, (b) 5 s, (c)
 s?

2. The nearest star beyond the Sun is Alpha Centauri, which is
 m away. If we were to receive a radio message from this star today, show that it would have been sent
 s ago (4.4 yr ago).