Since the boulder is raised with constant velocity, the net force on the boulder is zero, so that the boulder has weight 175 N on this planet. If its mass is 87.5 kg, then the acceleration due to gravity is g such that
175 N = (87.5 kg) g ⇒ g = (175 N) / (87.5 kg) = 2.00 N/kg = 2.00 m/s²