A speaker fixed to a moving platform moves toward a wall, emitting a steady sound with a frequency of 225 hz. A person on the platform right next to the speaker detects the sound waves reflected off the wall and those emitted by the speaker.

28. the new systematic nomenclature was so ( that many chemists preferred to ( the older trivial names that were at least shorter. at least, that is the ostensible reason. actually, tradition seems to carry more weight than ( with some scientists.