Vibration of vibration are pulling a child back on a swing and letting it go, or hitting a tuning fork and letting it ring. The mechanical system vibrates at one or more of its natural frequencies and damps down to motionlessness. Forced vibration is when a time-varying disturbance (load, displacement or velocity) is applied to a mechanical system. The disturbance can be a periodic and steady-state input, a transient input, or a random input. The periodic input can be a harmonic or a non-harmonic disturbance. Examples of these types of vibration include a washing machine shaking due to an imbalance, transportation
Oh Dear! What Can the Matter Be? And nobody knew she was there. The second old lady was Abigail Splatter. She went there 'cause something was definitely the matter. But when she got there, it was only her bladder, And nobody knew she was there. </poem> One suggested precursor to the bawdy song, recorded in William's "Upper Thames" collection is the following "old morris fragment": <poem> Oh, dear, what can the matter be? Three old women tied to an apple tree! One ran away, the others stopped till Saturday. Oh, dear, what can the matter be? </poem> As with many folk songs and tall tales each verse