The plunger is forced to undergo a simple harmonic vibration parallel to the direction of the tube . 活塞在平行于长管的方向被迫作合谐摆动。
2.
The simplest form of wave motion consists of the combination of a transverse simple harmonic vibration and a uniform translation . 波动的最简单形式是横向简谐振动和匀速直线运动的组合。