part (1 of 3 ). A 15 metric ton train moves toward the south at 70 m/s. At what speed must it travel to have five times its original momentum? A metric ton is 1000 kg. Answer in units of m/s. and Part (2 of 3 ). At what speed must it travel to have a momentum of 5 × 105 kg · m/s? Answer in units of m/s. and Part (3 of 3). If there were a speed limit for this train as it traveled through a city, but not a weight limit, what mass must be added to the train to slow it down to 10 m/s while at the same time keeping the momentum the same as in the second part? Answer in units of kg. THANK YOU!!