The highest land speed for a rail-guided vehicle was set in 1982 by a rocket sled at Holloman Air Force Base in southern New Mexico. The sled was unmanned, but if it had a payload with a mass of 25 kg, the magnitude of the payload’s momentum would have been 6. 8 × 104 kg• m/s. What was the speed, in m/s and km/h, of the payload and sled?
