A comet moves about the Sun in an elliptical orbit, with its closest approach to the Sun being about 0.680 AU and its greatest distance from the sun being 38.5 AU (1 AU = the Earth-Sun distance). The angular momentum of the comet about the Sun is constant, and the gravitational force exerted by the Sun has zero moment arm. The comet's speed at closest approach is 54.0 km/s. What is its speed when it is farthest from the Sun?
km/s