Mass-velocity relation of the SiO (5−4) outflow associated with MM1 in MDC310 (a) and MM1 in MDC684 (b), calculated from the SMA data for the gas mass in each channel, with each channel being 1.12 km s⁻¹ in width. The blue plus symbol denotes the measurement for the blueshifted lobe, and the red plus symbol indicates that for the redshifted lobe. Solid blue and red lines indicate broken power-law fittings to the blueshifted and redshifted lobes, respectively.