The orbit of Halley's Comet around the Sun is a thin long ellipse. At its aphelion (point uttermost from the Sun), the comet is 5.7 x 1012 m from the Sun and moves with the speed of 14.0 km/s. Determine the comet's speed at its perihelion (closest approach to the Sun) where its distance from the Sun is around 8.1 x 1010 m?