drop test in ansys ls-dyna

hi,

i am sunil kumar , this is my very first letter to this forum .

i am working on ansys-lsdyna drop test module , please if any one working on that module respond to me . i am dropping a aluminium block on to a rigid surface from 1.5m height , i need to get out put acceleration around (37000 m/s2) but i am getting too high as (250000 m/s2) in vertical direction at the time of impact .

can you suggest me where that i may commit a mistake in doing that.