It has been suggested that rail guns based on this principle could accelerate payloads into earth orbit or beyond. find the distance the bar must travel along the rails if it is to reach the escape speed for the earth (11.2 km/s). let b = 0.70 t , i = 1800 a , m = 21 kg , and l = 45 cm . for simplicity, assume the net force on the object is equal to the magnetic force, as in parts a and b, even though gravity plays an important role in an actual launch into space.