Question 1084458
… that the average acceleration was (inserting unit conversion factor for km/hr —> km/sec):

 (0km/hr - 100km/hr) * (1hr/3600s)  / (0.5 s)

  =   (-100 km/3600s) / (0.5s)
  =  (-0.55556 km/s^2)    
   = {{{ highlight( -555.56 ) }}} m/s^2

—
That's  over 56g's   (555.56/9.806).   Might not be a survivable situation.