Final answer:
The 'slowest waves' could refer to different wave types; ocean waves like tsunamis travel quickly across oceans but have a slow appearance near shores, while ELF electromagnetic waves are slow in frequency and useful for underwater communication.
Step-by-step explanation:
The term 'slowest waves' can refer to multiple types of waves, including ocean waves, sound waves, and electromagnetic waves. In the context of ocean waves, tidal waves or tsunamis can seem relatively slow as they approach the shore although they travel rapidly across the ocean. Electromagnetic waves such as ELF waves, or extremely low frequency waves, are among the slowest in terms of frequency and are used for submarine communications. Water waves in general travel much slower than sound waves; for instance, in a swimming pool, waves may propagate at a mere 0.75 m/s. Contrastingly, in the realm of sound, the speed of sound in dry air at 20°C is about 343.5 m/s, and ultrasonic waves are even faster and higher in frequency.
When examining specific examples, ocean waves created by storms in the South Pacific can take a substantial amount of time to reach the California coast if they travel at 15.0 m/s, covering the 12,000 km distance. Moreover, the speed at which a wave moves horizontally across a medium is distinct from the motion of objects, like seabirds, bobbing up and down on the wave itself. Understanding the various speeds of different wave types is crucial in applying them effectively in practical situations like communication and medical imaging.