Astronauts traveling toward Earth in a fastmoving
spacecraft receive a radio signal from an
antenna on Earth. Compared to the frequency
and wavelength of the radio signal emitted from
the antenna, the radio signal received by the
astronauts has a
(1) lower frequency and a shorter wavelength
(2) lower frequency and a longer wavelength
(3) higher frequency and a shorter wavelength
(4) higher frequency and a longer wavelength