[填空题]
An earthquake-produced sp4i3r 9p ms-v8rw8v8 bwbt3oc/wqx 3 :ct:akms,z(quurface wave can be approximated by a sinusoidal transverse wave. Assuming a frequency of 0.50 Hz (typical of earthquakes, which actually include a mixture of fw:uq3tmxq c(k ,z a:s/requencies), what amplitude is needed so that objects begin to leave contact with the ground? [Hint: Set the acceleration a>g] m
