Passage VII
Planets revolve around the Sun in elliptical orbits, as shown in Figure 1.
The eccentricity of an elongated the ellipse describes its elongation; the more elongated the ellipse, the greater its eccentricity. The semimajor axis is half the length of the ellipse.
Perihelion (Angle θ = 0°) is the point on the orbit closest to the Sun; aphelion (θ = 180°) is the point on the orbit farthest the Sun. The speed of a planet varies with θ.The speed of a planet versus θ is shown in Figure 2 for orbits with various eccentricities and semimajor axes.
40. Based on the data in Figure 2, for a planet in an orbit around the Sun with a semimajor axis of 3.0x 108 km and an eccentricity of 0.05, the speed at θ = 0° will be:
Your Answer is
Correct Answer is F
Explanation
From figure 2 as a whole, it can be seen that the smaller the eccentricity, the smaller the corresponding speed when θ=0°.
Looking at the second picture in figure 2, when the eccentricity is 0.1 and θ=0°, the speed is about 23 km/sec.