Earth is the homeworld of the Human race, located in the Sol System. It is the third planet of the system, orbiting at precisely 1 AU from its parent star, a G2-V Main Sequence star known as Sol, or simply The Sun. Contrary to popular belief, Earth is not the Federation's headquarters - it is Mars.
What causes whole body vibration. Drivers of some mobile machines, including certain tractors, fork lift trucks and quarrying or earth-moving machinery, may be exposed to WBV and shocks, which are associated with back pain.
Free vibration takes placewhen the system oscillates due to the action of internal forces only. Forced vibration is caused by the action ofexternal forces. If the frequency of excitation coincides with the natural frequency of the system, resonanceoccurs.