Complex sentence: Looking down into one's lap to consult a map or attempting to read a book while a passenger in a car may also bring on motion sickness.for vertical sinusoidal motion in the frequency range of 0.083-0.5 Hz and is maximal at 0.167 Hz.
Split into simpler sentences: Looking down into one's lap to consult a map or attempting to read a book while a passenger in a car may also bring on motion sickness. Motion sickness is greatest for vertical sinusoidal motion in the frequency range of 0.083-0.5 Hz and is maximal at 0.167 Hz.