How are radar and an approaching siren different? How are they similar? A. Radar uses sound waves, and the siren uses radio, but both exhibit
the Doppler effect
B. Radar uses radio, and the siren uses sound waves, but both exhibit
the Doppler effect
C. The Doppler effect can be observed only with radar, but both
devices use sound waves.
D. The Doppler effect can be observed only in the approaching siren,
but both devices use radio.