real function acc(theta)
      real theta
      real H,L
      H=2.0 !mm
      L=20.0 !mm
      tant=abs(tan(theta))
      if (L*tant.gt.H) then
        acc=0.5*H**2/tant
      else
        acc=L*(H-0.5*L*tant)
      endif
      end
       
      real function acc2(theta)
      real theta
      real H,L
      H=2.0 !mm
      L=20.0 !mm
      tant=abs(tan(theta))
      if (2*H/tant.lt.L) then
        acc2=H**2/tant
      else if (2*H/tant.gt.L .and. H/tant.lt.L) then
        acc2=H**2/tant-0.5*tant*(2*H/tant-L)**2
      else
        acc2=0.5*L**2*tant
      endif
      end