This exercise focuses on exploring orbital motion of the planets in the Solar System. From the Kepler's law we know that orbits of the planets are elliptics, the Sun being one of the foci of the ellipses. By drawing two ellipses and calculating their eccentricity, we see the relatiotionship between ovalness, eccentricity and the location of foci in the orbits. As indicated in Figure on the next page, fix the graph paper on a cardboard using pins. Get about 15 centimeters (cm) long srting and tie a knot of the open ends to make a loop. Draw first ellipse by separating two push pins about 3 cm; using the string loop and pencil as shown in the picture. Label it ellipse 1. Draw second ellipse by separating the two push pins about 6 cm. Label it ellipse 2. Draw semimajor axis. Mark pin pricks as f1 and f2 to represent the foci of the ellipse as shown in the sketch. Measure the distance between the foci and record it as B in the blank space below with proper unit. Now measure the distance between f1 and perihelion and represent it as A. Repeat this for ellipse 2 as well. By