Shock Duration We may approximate the displacement of the product on the cushion, at any time during the impact with the function: 13.20 where 13.21 f2 - the natural frequency of the product (M2) on the cushion (k2). ( ) sin( ) 2 2 x t d t  m  2 2 2  = f 2 2 2 2 1 W k g f  =Shock Duration We may approximate the displacement of the product on the cushion, at any time during the impact with the function: 13.20 where 13.21 f2 - the natural frequency of the product (M2) on the cushion (k2). ( ) sin( ) 2 2 x t d t  m  2 2 2  = f 2 2 2 2 1 W k g f  =